LHC Physics

Alan Barr UCL

This morningrsquos stuffhellip

Higgs ndash why we expect it how to look for it hellip

Supersymmetry ndash similar questions

Smorgasbord of other LHC physics

Physics at TeV-scale

bull Dominated by the physics ofElectroweak Symmetry Breaking

bull Answering the question ndash ldquoWhy do the W and Z bosons have massrdquo

bull Standard Model suggests Higgs mechanismndash However Higgs boson predicted by SM not

yet observed

Higgs mechanism - historybull 1964 Demonstration that a scalar field with

appropriate interactions can give mass to gauge bosonsndash Peter Higgs (Edinburgh previously UCL) ndash Independently discovered by Francois Englert and

Robert Brout (Brussels)

bull Not until 1979 that Salam Weinberg and Glashow use this in a theory of electroweak symmetry breaking ndash For a biographic article on P Higgs see

httpphysicsweborgarticlesworld1776

Higgs mechanism - historybull 1964 Demonstration that a scalar field with

appropriate interactions can give mass to gauge bosonsndash Peter Higgs (Edinburgh previously UCL) ndash Independently discovered by Francois Englert and

Robert Brout (Brussels)

bull Not until 1979 that Salam Weinberg and Glashow use this in a theory of electroweak symmetry breaking ndash For a biographic article on P Higgs see

httpphysicsweborgarticlesworld1776

Higgs mechanism why needed

bull Example of P Higgs ndash give mass to a U(1) boson (heavy ldquophotonrdquo in a QED-like theory)

Start with QED Lagrangian

Which is invariant under the local U(1) gauge transformation

But this isnrsquot invariant under gauge transformation () so is not allowed

Adding a gauge boson mass term could be attempted with a term like

where

()

Instead add a complex scalar field which couples to the gauge boson Instead add a complex scalar field which couples to the gauge boson

Pictorial representation

Scalar field strength = 0

Degenerate minimumVacuum (field strengthne0)

Quartic term self-couplingpositive

Quadratic coupling termnegative

Excitations in this direction produce physical Higgs boson

Excitations in this direction produce physical Higgs boson

Excitations in this direction = gauge transformation- Global transformationsunobserved- Local transformations give mass to gauge bosons

Excitations in this direction = gauge transformation- Global transformationsunobserved- Local transformations give mass to gauge bosons

If you donrsquot understand this study PhysLett12132-1331964

Higgs field ldquoeats Goldstone bosonrdquo

bull Flat direction in potential usually represents zero-mass particlendash ldquoGoldstone bosonrdquo

bull But in Higgs theory this direction is coupled to the gauge bosonndash No massless Goldstone bosonndash Instead mass term generated for

gauge boson

φφ

Gauge boson

Example of a Feynmandiagram showing a contribution to the gaugeboson mass term

NB Our example here was for a single complex scalar and for a U(1) fieldIn the Standard Model the Higgs is an electroweak SU(2) doublet field with 4 degrees of freedom 3 of these are lsquoeatenrsquo by Wplusmn Z0 mass terms leaving a single scalar for the physical Higgs boson

For full SU(2) treatment see eg Halzen amp Martin section 149

NB Our example here was for a single complex scalar and for a U(1) fieldIn the Standard Model the Higgs is an electroweak SU(2) doublet field with 4 degrees of freedom 3 of these are lsquoeatenrsquo by Wplusmn Z0 mass terms leaving a single scalar for the physical Higgs boson

For full SU(2) treatment see eg Halzen amp Martin section 149

φ

Pictorial representation

Scalar field strength = 0

Degenerate minimumVacuum (field strengthne0)

Quartic term self-couplingpositive

Quadratic coupling termnegative

Excitations in this direction produce physical Higgs boson

Excitations in this direction produce physical Higgs boson

Excitations in this direction = gauge transformation- Global transformationsunobserved- Local transformations give mass to gauge bosons

Excitations in this direction = gauge transformation- Global transformationsunobserved- Local transformations give mass to gauge bosons

If you donrsquot understand this study PhysLett12132-1331964

Higgs field ldquoeats Goldstone bosonrdquo

bull Flat direction in potential usually represents zero-mass particlendash ldquoGoldstone bosonrdquo

bull But in Higgs theory this direction is coupled to the gauge bosonndash No massless Goldstone bosonndash Instead mass term generated for

gauge boson

φφ

Gauge boson

Example of a Feynmandiagram showing a contribution to the gaugeboson mass term

NB Our example here was for a single complex scalar and for a U(1) fieldIn the Standard Model the Higgs is an electroweak SU(2) doublet field with 4 degrees of freedom 3 of these are lsquoeatenrsquo by Wplusmn Z0 mass terms leaving a single scalar for the physical Higgs boson

For full SU(2) treatment see eg Halzen amp Martin section 149

NB Our example here was for a single complex scalar and for a U(1) fieldIn the Standard Model the Higgs is an electroweak SU(2) doublet field with 4 degrees of freedom 3 of these are lsquoeatenrsquo by Wplusmn Z0 mass terms leaving a single scalar for the physical Higgs boson

For full SU(2) treatment see eg Halzen amp Martin section 149

φ

Higgs field ldquoeats Goldstone bosonrdquo

bull Flat direction in potential usually represents zero-mass particlendash ldquoGoldstone bosonrdquo

bull But in Higgs theory this direction is coupled to the gauge bosonndash No massless Goldstone bosonndash Instead mass term generated for

gauge boson

φφ

Gauge boson

Example of a Feynmandiagram showing a contribution to the gaugeboson mass term

NB Our example here was for a single complex scalar and for a U(1) fieldIn the Standard Model the Higgs is an electroweak SU(2) doublet field with 4 degrees of freedom 3 of these are lsquoeatenrsquo by Wplusmn Z0 mass terms leaving a single scalar for the physical Higgs boson

For full SU(2) treatment see eg Halzen amp Martin section 149

NB Our example here was for a single complex scalar and for a U(1) fieldIn the Standard Model the Higgs is an electroweak SU(2) doublet field with 4 degrees of freedom 3 of these are lsquoeatenrsquo by Wplusmn Z0 mass terms leaving a single scalar for the physical Higgs boson

For full SU(2) treatment see eg Halzen amp Martin section 149

φ

Constraints on the Higgs mass

bull Higgs boson mass is the remaining unpredicted parameter in Standard Model

bull Higgs self-couplings not predictedbull So Higgs mass not predicted by Electroweak theory

bull However there are1 Bounds from theory

bull Perterbative unitarity of boson-boson scattering

2 Indirect boundsbull Loop effects on gauge boson masses

3 Direct boundsbull Searches

PhysRevD1615191977 Without other new physics the Higgs boson must exist amp have mass lt 1 TeV

Vector Boson scattering

Perturbative limit

Halzen amp Martin section 156

Indirect Higgs bounds LEP Electroweak data

bull W (and Z) mass depends on mHiggsndash Logarithmic loop corrections to

massesndash Also depends on top mass

bull W (and Z) mass depends on mHiggsndash Logarithmic loop corrections to

massesndash Also depends on top mass

httplepewwgwebcernchLEPEWWG

Measurements

Prediction as a function of mH

Direct boundsHiggs searches LEP

bull No discoverybull Direct lower bound at 1144 GeV

PhysLett B565 (2003) 61-75

Higgsstrahlung ndash dominant production

ALEPHCandidate vertex

Higgs-Hunter Situation Report

bull Something very much like the Higgs must exist with ~100 GeV lt m lt ~1 TeV

bull No discovery as yetbull If it is a Standard Model Higgs the constraints are

tighter 1144 GeV lt mSM Higgs lt 199 GeV

The Large Hadron Collider

bull Largendash 27 km circumferencendash Built in LEP tunnel

bull Hadron ndash Mostly protonsndash Can also collide ions

bull Colliderndash ~ 7 x higher collision

energyndash ~ 100 x increase in

luminosityndash Compared to Tevatron

Proton on Protonat radics = 14 TeV

Design luminsoity ~~100 fb-1 expt year

General Purpose Detectors

ATLAS

Similarities1 Tracker2 Calorimeter3 Muon chambers

DifferencesSize CMS ldquocompactrdquoMagnetic-field configurationATLAS has muon toroidsElectromagnetic-CalorimeterCMS crystals ATLAS Liquid ArgonOuter tracker technologyCMS all-silicon ATLAS straw tubes

PhysRevD1615191977 Without other new physics the Higgs boson must exist amp have mass lt 1 TeV

Vector Boson scattering

Perturbative limit

Halzen amp Martin section 156

Indirect Higgs bounds LEP Electroweak data

bull W (and Z) mass depends on mHiggsndash Logarithmic loop corrections to

massesndash Also depends on top mass

bull W (and Z) mass depends on mHiggsndash Logarithmic loop corrections to

massesndash Also depends on top mass

httplepewwgwebcernchLEPEWWG

Measurements

Prediction as a function of mH

Direct boundsHiggs searches LEP

bull No discoverybull Direct lower bound at 1144 GeV

PhysLett B565 (2003) 61-75

Higgsstrahlung ndash dominant production

ALEPHCandidate vertex

Higgs-Hunter Situation Report

bull Something very much like the Higgs must exist with ~100 GeV lt m lt ~1 TeV

bull No discovery as yetbull If it is a Standard Model Higgs the constraints are

tighter 1144 GeV lt mSM Higgs lt 199 GeV

The Large Hadron Collider

bull Largendash 27 km circumferencendash Built in LEP tunnel

bull Hadron ndash Mostly protonsndash Can also collide ions

bull Colliderndash ~ 7 x higher collision

energyndash ~ 100 x increase in

luminosityndash Compared to Tevatron

Proton on Protonat radics = 14 TeV

Design luminsoity ~~100 fb-1 expt year

General Purpose Detectors

ATLAS

Similarities1 Tracker2 Calorimeter3 Muon chambers

DifferencesSize CMS ldquocompactrdquoMagnetic-field configurationATLAS has muon toroidsElectromagnetic-CalorimeterCMS crystals ATLAS Liquid ArgonOuter tracker technologyCMS all-silicon ATLAS straw tubes

Indirect Higgs bounds LEP Electroweak data

bull W (and Z) mass depends on mHiggsndash Logarithmic loop corrections to

massesndash Also depends on top mass

bull W (and Z) mass depends on mHiggsndash Logarithmic loop corrections to

massesndash Also depends on top mass

httplepewwgwebcernchLEPEWWG

Measurements

Prediction as a function of mH

Direct boundsHiggs searches LEP

bull No discoverybull Direct lower bound at 1144 GeV

PhysLett B565 (2003) 61-75

Higgsstrahlung ndash dominant production

ALEPHCandidate vertex

Higgs-Hunter Situation Report

bull Something very much like the Higgs must exist with ~100 GeV lt m lt ~1 TeV

bull No discovery as yetbull If it is a Standard Model Higgs the constraints are

tighter 1144 GeV lt mSM Higgs lt 199 GeV

The Large Hadron Collider

bull Largendash 27 km circumferencendash Built in LEP tunnel

bull Hadron ndash Mostly protonsndash Can also collide ions

bull Colliderndash ~ 7 x higher collision

energyndash ~ 100 x increase in

luminosityndash Compared to Tevatron

Proton on Protonat radics = 14 TeV

Design luminsoity ~~100 fb-1 expt year

General Purpose Detectors

ATLAS

Similarities1 Tracker2 Calorimeter3 Muon chambers

DifferencesSize CMS ldquocompactrdquoMagnetic-field configurationATLAS has muon toroidsElectromagnetic-CalorimeterCMS crystals ATLAS Liquid ArgonOuter tracker technologyCMS all-silicon ATLAS straw tubes

Direct boundsHiggs searches LEP

bull No discoverybull Direct lower bound at 1144 GeV

PhysLett B565 (2003) 61-75

Higgsstrahlung ndash dominant production

ALEPHCandidate vertex

Higgs-Hunter Situation Report

bull Something very much like the Higgs must exist with ~100 GeV lt m lt ~1 TeV

bull No discovery as yetbull If it is a Standard Model Higgs the constraints are

tighter 1144 GeV lt mSM Higgs lt 199 GeV

The Large Hadron Collider

bull Largendash 27 km circumferencendash Built in LEP tunnel

bull Hadron ndash Mostly protonsndash Can also collide ions

bull Colliderndash ~ 7 x higher collision

energyndash ~ 100 x increase in

luminosityndash Compared to Tevatron

Proton on Protonat radics = 14 TeV

Design luminsoity ~~100 fb-1 expt year

General Purpose Detectors

ATLAS

Similarities1 Tracker2 Calorimeter3 Muon chambers

DifferencesSize CMS ldquocompactrdquoMagnetic-field configurationATLAS has muon toroidsElectromagnetic-CalorimeterCMS crystals ATLAS Liquid ArgonOuter tracker technologyCMS all-silicon ATLAS straw tubes

Higgs-Hunter Situation Report

bull Something very much like the Higgs must exist with ~100 GeV lt m lt ~1 TeV

bull No discovery as yetbull If it is a Standard Model Higgs the constraints are

tighter 1144 GeV lt mSM Higgs lt 199 GeV

The Large Hadron Collider

bull Largendash 27 km circumferencendash Built in LEP tunnel

bull Hadron ndash Mostly protonsndash Can also collide ions

bull Colliderndash ~ 7 x higher collision

energyndash ~ 100 x increase in

luminosityndash Compared to Tevatron

Proton on Protonat radics = 14 TeV

Design luminsoity ~~100 fb-1 expt year

General Purpose Detectors

ATLAS

Similarities1 Tracker2 Calorimeter3 Muon chambers

DifferencesSize CMS ldquocompactrdquoMagnetic-field configurationATLAS has muon toroidsElectromagnetic-CalorimeterCMS crystals ATLAS Liquid ArgonOuter tracker technologyCMS all-silicon ATLAS straw tubes

The Large Hadron Collider

bull Largendash 27 km circumferencendash Built in LEP tunnel

bull Hadron ndash Mostly protonsndash Can also collide ions

bull Colliderndash ~ 7 x higher collision

energyndash ~ 100 x increase in

luminosityndash Compared to Tevatron

Proton on Protonat radics = 14 TeV

Design luminsoity ~~100 fb-1 expt year

General Purpose Detectors

ATLAS

Similarities1 Tracker2 Calorimeter3 Muon chambers

DifferencesSize CMS ldquocompactrdquoMagnetic-field configurationATLAS has muon toroidsElectromagnetic-CalorimeterCMS crystals ATLAS Liquid ArgonOuter tracker technologyCMS all-silicon ATLAS straw tubes

General Purpose Detectors

ATLAS

Similarities1 Tracker2 Calorimeter3 Muon chambers

DifferencesSize CMS ldquocompactrdquoMagnetic-field configurationATLAS has muon toroidsElectromagnetic-CalorimeterCMS crystals ATLAS Liquid ArgonOuter tracker technologyCMS all-silicon ATLAS straw tubes

Definitions

z

z

pE

pEy

log21

BarrelldquoCentralrdquo

EndcapldquoForwardrdquo

EndcapldquoForwardrdquo

Beam pipe

proton proton

x

y

φ

θ

Particle

Rapidity

Pseudorapidity )]2ln[tan(

Differences in rapidity are conservedunder Lorentz boosts in the z-direction

Good approximation to rapidity if Egtgtm

η = 0η = -1

z

ldquoTransverserdquo pT = (px py) |pT| = radic(px2 py

2)

η = -2

η = -3

η = +1

η = +2

η = +3

prove these

Making particles in hadron colliders

bull Hadron-Hadron collisions complicatedndash See lectures by Mark Lancaster

(ldquoHadron Collider Physicsrdquo)ndash QCD Lots of background events with jetsndash QCD Lots of hadronic ldquorubbishrdquo in signal events ndash Hard scatters are largely from q-qbar or glue-glue

bull Proton structure is important ndash See lectures by Robert Thorne

bull But they provide the highest energies availablebull Often these are the discovery machines

proton proton

LHCb

bull Asymmetric detector for B-meson physics

For more information see Lazzeroni talk athttpindicocernchconferenceDisplaypyconfId=5426

Making particles in hadron colliders

bull Hadron-Hadron collisions complicatedndash See lectures by Mark Lancaster

(ldquoHadron Collider Physicsrdquo)ndash QCD Lots of background events with jetsndash QCD Lots of hadronic ldquorubbishrdquo in signal events ndash Hard scatters are largely from q-qbar or glue-glue

bull Proton structure is important ndash See lectures by Robert Thorne

bull But they provide the highest energies availablebull Often these are the discovery machines

proton proton

LHCb

bull Asymmetric detector for B-meson physics

For more information see Lazzeroni talk athttpindicocernchconferenceDisplaypyconfId=5426

LHCb

bull Asymmetric detector for B-meson physics

For more information see Lazzeroni talk athttpindicocernchconferenceDisplaypyconfId=5426

LHCb Physics

bull VCKM must be unitary VVdagger = V daggerV = 1

bull Multiply out rows amp columns

Quark flavour e-states are not the same as mass e-states mixing

Do thisDo this

LHCb Physics

bull Measurements of decay rates and kinematics tell us about squark mixings

bull Over-constraining triangles gives sensitivity to new physics through loop effects

bull Signals for QGPndash Jet quenching

ndash Quarkonim (eg Jψ) suppression (ldquomelt bound statesrdquo)

ALICEbull Designed to examine

collisions of heavy ions (eg lead-lead or gold-gold)

bull Theorised to produce a new state of matter ndash a quark-gluon plasma

bull Quarks no longer confined inside colourless baryons

QGP JetNo Jet

Jψ c

c

_

Couplings of the SM Higgs

bull Couplings proportional to mass

bull What does this mean for the Higgs-hunter

Producing a Higgs

bull Higgs couplings massndash u-ubar H

has very small cross-section

ndash Dominant production via vertices coupling Higgs to heavy quarks or WZ bosons

bull Higgs couplings massndash u-ubar H

has very small cross-section

ndash Dominant production via vertices coupling Higgs to heavy quarks or WZ bosons

Production cross-sections

Decay of the SM Higgs

bull Width becomes large as WW mode opensbull Branching ratios change rapidly as new

channels become kinematically accessible

Needle in a haystackhellip

Higgs production

QCD jet productionat high energy

Need to use signatures with small backgrounds- Leptons- High-mass resonances- Heavy quarksto avoid being overwhelmed

Need to use signatures with small backgrounds- Leptons- High-mass resonances- Heavy quarksto avoid being overwhelmed

Example 1 H ZZ

bull Only works when mHiggs gt~ 2MZ

bull When the Z decays to leptons there are small backgrounds

q

q_ H

Z

Z

e+

e-

e+

e-

H ZZ

H ZZ e+e- e+e-H ZZ e+e- e+e-

CMS

Electrons have track (green ) amp energy deposit (pink)

H ZZ e+e- e+e-

Plot shows simulated distributions of [invariant mass of four electrons] for 3 different values of mHiggs(We wouldnrsquot see all of these together)

q

q_ H

Z

Z

e+

e-

e+

e-

1 Find events consistent with above topology(four electrons)

2 Add together the fourelectron 4-vectors

3 Find the mass of the resultant4-vector ( mass of the Higgs)

mH=130mH=170

mH=150

background

Example (2) H γγbull No direct coupling

of H to photonbull However allowed at

loop levelbull Branching ratio

~ 10 -3

(at low mHiggs)bull Important at low

massbull Actually a very

clean way of looking for Higgsndash Small backgrounds

Production and decay of Higgsthrough lsquoforbiddenrsquo direct couplings

H γγ CMS simulation Physics TDR 2006H γγ CMS simulation Physics TDR 2006

γ

γ

H γγ

bull Simulation by CMS for different Higgs massesfor early LHC data (1 fb-1)

Higgs signalscaled up by factor 10

Invariant mass of the pair of photons

H γγ hellip backgrounds

ldquoIrreduciblerdquo2 real photons

ldquoReduciblerdquoeg fake photons

γ

gluon

q

q_

π0

γγ

Need v good calorimetersegmentationto separate these

ldquoBornrdquo ldquoBoxrdquo

Significance

H-gtZZ

Significance is a measureof the answer to the questionldquoWhat is the probabilitythat a backgroundfluctuation would producewhat I am seeingrdquo

5- means ldquoprobabilitythat background fluctuation does this is less than 28510-7 rdquo

5- is usually takenas benchmarkfor ldquodiscoveryrdquo

After discovery of Higgs

bull Measure Higgs massndash The remaining unconstrained parameter of the Standard Model

bull Measure Higgs couplings to fermions and vector bosonsndash All predicted by Standard Modelndash Check Higgs mechanism

bull Couplings very important since there may be more than one Higgs bosonndash Theories beyond the Standard Model (such as Supersymmetry)

predict multiple Higgs bosonsndash In such models the couplings would be modified

bull Do direct searches for further Higgs bosons

If no Higgs found

bull Arguably more exciting than finding Higgsbull Look at WW scattering process

ndash Look for whatever is ldquofixingrdquo the cross-sectionndash Eg exotic resonances

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

LHCb Physics

bull Measurements of decay rates and kinematics tell us about squark mixings

bull Over-constraining triangles gives sensitivity to new physics through loop effects

bull Signals for QGPndash Jet quenching

ndash Quarkonim (eg Jψ) suppression (ldquomelt bound statesrdquo)

ALICEbull Designed to examine

collisions of heavy ions (eg lead-lead or gold-gold)

bull Theorised to produce a new state of matter ndash a quark-gluon plasma

bull Quarks no longer confined inside colourless baryons

QGP JetNo Jet

Jψ c

c

_

Couplings of the SM Higgs

bull Couplings proportional to mass

bull What does this mean for the Higgs-hunter

Producing a Higgs

bull Higgs couplings massndash u-ubar H

has very small cross-section

ndash Dominant production via vertices coupling Higgs to heavy quarks or WZ bosons

bull Higgs couplings massndash u-ubar H

has very small cross-section

ndash Dominant production via vertices coupling Higgs to heavy quarks or WZ bosons

Production cross-sections

Decay of the SM Higgs

bull Width becomes large as WW mode opensbull Branching ratios change rapidly as new

channels become kinematically accessible

Needle in a haystackhellip

Higgs production

QCD jet productionat high energy

Need to use signatures with small backgrounds- Leptons- High-mass resonances- Heavy quarksto avoid being overwhelmed

Need to use signatures with small backgrounds- Leptons- High-mass resonances- Heavy quarksto avoid being overwhelmed

Example 1 H ZZ

bull Only works when mHiggs gt~ 2MZ

bull When the Z decays to leptons there are small backgrounds

q

q_ H

Z

Z

e+

e-

e+

e-

H ZZ

H ZZ e+e- e+e-H ZZ e+e- e+e-

CMS

Electrons have track (green ) amp energy deposit (pink)

H ZZ e+e- e+e-

Plot shows simulated distributions of [invariant mass of four electrons] for 3 different values of mHiggs(We wouldnrsquot see all of these together)

q

q_ H

Z

Z

e+

e-

e+

e-

1 Find events consistent with above topology(four electrons)

2 Add together the fourelectron 4-vectors

3 Find the mass of the resultant4-vector ( mass of the Higgs)

mH=130mH=170

mH=150

background

Example (2) H γγbull No direct coupling

of H to photonbull However allowed at

loop levelbull Branching ratio

~ 10 -3

(at low mHiggs)bull Important at low

massbull Actually a very

clean way of looking for Higgsndash Small backgrounds

Production and decay of Higgsthrough lsquoforbiddenrsquo direct couplings

H γγ CMS simulation Physics TDR 2006H γγ CMS simulation Physics TDR 2006

γ

γ

H γγ

bull Simulation by CMS for different Higgs massesfor early LHC data (1 fb-1)

Higgs signalscaled up by factor 10

Invariant mass of the pair of photons

H γγ hellip backgrounds

ldquoIrreduciblerdquo2 real photons

ldquoReduciblerdquoeg fake photons

γ

gluon

q

q_

π0

γγ

Need v good calorimetersegmentationto separate these

ldquoBornrdquo ldquoBoxrdquo

Significance

H-gtZZ

Significance is a measureof the answer to the questionldquoWhat is the probabilitythat a backgroundfluctuation would producewhat I am seeingrdquo

5- means ldquoprobabilitythat background fluctuation does this is less than 28510-7 rdquo

5- is usually takenas benchmarkfor ldquodiscoveryrdquo

After discovery of Higgs

bull Measure Higgs massndash The remaining unconstrained parameter of the Standard Model

bull Measure Higgs couplings to fermions and vector bosonsndash All predicted by Standard Modelndash Check Higgs mechanism

bull Couplings very important since there may be more than one Higgs bosonndash Theories beyond the Standard Model (such as Supersymmetry)

predict multiple Higgs bosonsndash In such models the couplings would be modified

bull Do direct searches for further Higgs bosons

If no Higgs found

bull Arguably more exciting than finding Higgsbull Look at WW scattering process

ndash Look for whatever is ldquofixingrdquo the cross-sectionndash Eg exotic resonances

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

bull Signals for QGPndash Jet quenching

ndash Quarkonim (eg Jψ) suppression (ldquomelt bound statesrdquo)

ALICEbull Designed to examine

collisions of heavy ions (eg lead-lead or gold-gold)

bull Theorised to produce a new state of matter ndash a quark-gluon plasma

bull Quarks no longer confined inside colourless baryons

QGP JetNo Jet

Jψ c

c

_

Couplings of the SM Higgs

bull Couplings proportional to mass

bull What does this mean for the Higgs-hunter

Producing a Higgs

bull Higgs couplings massndash u-ubar H

has very small cross-section

ndash Dominant production via vertices coupling Higgs to heavy quarks or WZ bosons

bull Higgs couplings massndash u-ubar H

has very small cross-section

ndash Dominant production via vertices coupling Higgs to heavy quarks or WZ bosons

Production cross-sections

Decay of the SM Higgs

bull Width becomes large as WW mode opensbull Branching ratios change rapidly as new

channels become kinematically accessible

Needle in a haystackhellip

Higgs production

QCD jet productionat high energy

Need to use signatures with small backgrounds- Leptons- High-mass resonances- Heavy quarksto avoid being overwhelmed

Need to use signatures with small backgrounds- Leptons- High-mass resonances- Heavy quarksto avoid being overwhelmed

Example 1 H ZZ

bull Only works when mHiggs gt~ 2MZ

bull When the Z decays to leptons there are small backgrounds

q

q_ H

Z

Z

e+

e-

e+

e-

H ZZ

H ZZ e+e- e+e-H ZZ e+e- e+e-

CMS

Electrons have track (green ) amp energy deposit (pink)

H ZZ e+e- e+e-

Plot shows simulated distributions of [invariant mass of four electrons] for 3 different values of mHiggs(We wouldnrsquot see all of these together)

q

q_ H

Z

Z

e+

e-

e+

e-

1 Find events consistent with above topology(four electrons)

2 Add together the fourelectron 4-vectors

3 Find the mass of the resultant4-vector ( mass of the Higgs)

mH=130mH=170

mH=150

background

Example (2) H γγbull No direct coupling

of H to photonbull However allowed at

loop levelbull Branching ratio

~ 10 -3

(at low mHiggs)bull Important at low

massbull Actually a very

clean way of looking for Higgsndash Small backgrounds

Production and decay of Higgsthrough lsquoforbiddenrsquo direct couplings

H γγ CMS simulation Physics TDR 2006H γγ CMS simulation Physics TDR 2006

γ

γ

H γγ

bull Simulation by CMS for different Higgs massesfor early LHC data (1 fb-1)

Higgs signalscaled up by factor 10

Invariant mass of the pair of photons

H γγ hellip backgrounds

ldquoIrreduciblerdquo2 real photons

ldquoReduciblerdquoeg fake photons

γ

gluon

q

q_

π0

γγ

Need v good calorimetersegmentationto separate these

ldquoBornrdquo ldquoBoxrdquo

Significance

H-gtZZ

Significance is a measureof the answer to the questionldquoWhat is the probabilitythat a backgroundfluctuation would producewhat I am seeingrdquo

5- means ldquoprobabilitythat background fluctuation does this is less than 28510-7 rdquo

5- is usually takenas benchmarkfor ldquodiscoveryrdquo

After discovery of Higgs

bull Measure Higgs massndash The remaining unconstrained parameter of the Standard Model

bull Measure Higgs couplings to fermions and vector bosonsndash All predicted by Standard Modelndash Check Higgs mechanism

bull Couplings very important since there may be more than one Higgs bosonndash Theories beyond the Standard Model (such as Supersymmetry)

predict multiple Higgs bosonsndash In such models the couplings would be modified

bull Do direct searches for further Higgs bosons

If no Higgs found

bull Arguably more exciting than finding Higgsbull Look at WW scattering process

ndash Look for whatever is ldquofixingrdquo the cross-sectionndash Eg exotic resonances

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Couplings of the SM Higgs

bull Couplings proportional to mass

bull What does this mean for the Higgs-hunter

Producing a Higgs

bull Higgs couplings massndash u-ubar H

has very small cross-section

ndash Dominant production via vertices coupling Higgs to heavy quarks or WZ bosons

bull Higgs couplings massndash u-ubar H

has very small cross-section

ndash Dominant production via vertices coupling Higgs to heavy quarks or WZ bosons

Production cross-sections

Decay of the SM Higgs

bull Width becomes large as WW mode opensbull Branching ratios change rapidly as new

channels become kinematically accessible

Needle in a haystackhellip

Higgs production

QCD jet productionat high energy

Need to use signatures with small backgrounds- Leptons- High-mass resonances- Heavy quarksto avoid being overwhelmed

Need to use signatures with small backgrounds- Leptons- High-mass resonances- Heavy quarksto avoid being overwhelmed

Example 1 H ZZ

bull Only works when mHiggs gt~ 2MZ

bull When the Z decays to leptons there are small backgrounds

q

q_ H

Z

Z

e+

e-

e+

e-

H ZZ

H ZZ e+e- e+e-H ZZ e+e- e+e-

CMS

Electrons have track (green ) amp energy deposit (pink)

H ZZ e+e- e+e-

Plot shows simulated distributions of [invariant mass of four electrons] for 3 different values of mHiggs(We wouldnrsquot see all of these together)

q

q_ H

Z

Z

e+

e-

e+

e-

1 Find events consistent with above topology(four electrons)

2 Add together the fourelectron 4-vectors

3 Find the mass of the resultant4-vector ( mass of the Higgs)

mH=130mH=170

mH=150

background

Example (2) H γγbull No direct coupling

of H to photonbull However allowed at

loop levelbull Branching ratio

~ 10 -3

(at low mHiggs)bull Important at low

massbull Actually a very

clean way of looking for Higgsndash Small backgrounds

Production and decay of Higgsthrough lsquoforbiddenrsquo direct couplings

H γγ CMS simulation Physics TDR 2006H γγ CMS simulation Physics TDR 2006

γ

γ

H γγ

bull Simulation by CMS for different Higgs massesfor early LHC data (1 fb-1)

Higgs signalscaled up by factor 10

Invariant mass of the pair of photons

H γγ hellip backgrounds

ldquoIrreduciblerdquo2 real photons

ldquoReduciblerdquoeg fake photons

γ

gluon

q

q_

π0

γγ

Need v good calorimetersegmentationto separate these

ldquoBornrdquo ldquoBoxrdquo

Significance

H-gtZZ

Significance is a measureof the answer to the questionldquoWhat is the probabilitythat a backgroundfluctuation would producewhat I am seeingrdquo

5- means ldquoprobabilitythat background fluctuation does this is less than 28510-7 rdquo

5- is usually takenas benchmarkfor ldquodiscoveryrdquo

After discovery of Higgs

bull Measure Higgs massndash The remaining unconstrained parameter of the Standard Model

bull Measure Higgs couplings to fermions and vector bosonsndash All predicted by Standard Modelndash Check Higgs mechanism

bull Couplings very important since there may be more than one Higgs bosonndash Theories beyond the Standard Model (such as Supersymmetry)

predict multiple Higgs bosonsndash In such models the couplings would be modified

bull Do direct searches for further Higgs bosons

If no Higgs found

bull Arguably more exciting than finding Higgsbull Look at WW scattering process

ndash Look for whatever is ldquofixingrdquo the cross-sectionndash Eg exotic resonances

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Producing a Higgs

bull Higgs couplings massndash u-ubar H

has very small cross-section

ndash Dominant production via vertices coupling Higgs to heavy quarks or WZ bosons

bull Higgs couplings massndash u-ubar H

has very small cross-section

ndash Dominant production via vertices coupling Higgs to heavy quarks or WZ bosons

Production cross-sections

Decay of the SM Higgs

bull Width becomes large as WW mode opensbull Branching ratios change rapidly as new

channels become kinematically accessible

Needle in a haystackhellip

Higgs production

QCD jet productionat high energy

Need to use signatures with small backgrounds- Leptons- High-mass resonances- Heavy quarksto avoid being overwhelmed

Need to use signatures with small backgrounds- Leptons- High-mass resonances- Heavy quarksto avoid being overwhelmed

Example 1 H ZZ

bull Only works when mHiggs gt~ 2MZ

bull When the Z decays to leptons there are small backgrounds

q

q_ H

Z

Z

e+

e-

e+

e-

H ZZ

H ZZ e+e- e+e-H ZZ e+e- e+e-

CMS

Electrons have track (green ) amp energy deposit (pink)

H ZZ e+e- e+e-

Plot shows simulated distributions of [invariant mass of four electrons] for 3 different values of mHiggs(We wouldnrsquot see all of these together)

q

q_ H

Z

Z

e+

e-

e+

e-

1 Find events consistent with above topology(four electrons)

2 Add together the fourelectron 4-vectors

3 Find the mass of the resultant4-vector ( mass of the Higgs)

mH=130mH=170

mH=150

background

Example (2) H γγbull No direct coupling

of H to photonbull However allowed at

loop levelbull Branching ratio

~ 10 -3

(at low mHiggs)bull Important at low

massbull Actually a very

clean way of looking for Higgsndash Small backgrounds

Production and decay of Higgsthrough lsquoforbiddenrsquo direct couplings

H γγ CMS simulation Physics TDR 2006H γγ CMS simulation Physics TDR 2006

γ

γ

H γγ

bull Simulation by CMS for different Higgs massesfor early LHC data (1 fb-1)

Higgs signalscaled up by factor 10

Invariant mass of the pair of photons

H γγ hellip backgrounds

ldquoIrreduciblerdquo2 real photons

ldquoReduciblerdquoeg fake photons

γ

gluon

q

q_

π0

γγ

Need v good calorimetersegmentationto separate these

ldquoBornrdquo ldquoBoxrdquo

Significance

H-gtZZ

Significance is a measureof the answer to the questionldquoWhat is the probabilitythat a backgroundfluctuation would producewhat I am seeingrdquo

5- means ldquoprobabilitythat background fluctuation does this is less than 28510-7 rdquo

5- is usually takenas benchmarkfor ldquodiscoveryrdquo

After discovery of Higgs

bull Measure Higgs massndash The remaining unconstrained parameter of the Standard Model

bull Measure Higgs couplings to fermions and vector bosonsndash All predicted by Standard Modelndash Check Higgs mechanism

bull Couplings very important since there may be more than one Higgs bosonndash Theories beyond the Standard Model (such as Supersymmetry)

predict multiple Higgs bosonsndash In such models the couplings would be modified

bull Do direct searches for further Higgs bosons

If no Higgs found

bull Arguably more exciting than finding Higgsbull Look at WW scattering process

ndash Look for whatever is ldquofixingrdquo the cross-sectionndash Eg exotic resonances

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Production cross-sections

Decay of the SM Higgs

bull Width becomes large as WW mode opensbull Branching ratios change rapidly as new

channels become kinematically accessible

Needle in a haystackhellip

Higgs production

QCD jet productionat high energy

Need to use signatures with small backgrounds- Leptons- High-mass resonances- Heavy quarksto avoid being overwhelmed

Need to use signatures with small backgrounds- Leptons- High-mass resonances- Heavy quarksto avoid being overwhelmed

Example 1 H ZZ

bull Only works when mHiggs gt~ 2MZ

bull When the Z decays to leptons there are small backgrounds

q

q_ H

Z

Z

e+

e-

e+

e-

H ZZ

H ZZ e+e- e+e-H ZZ e+e- e+e-

CMS

Electrons have track (green ) amp energy deposit (pink)

H ZZ e+e- e+e-

Plot shows simulated distributions of [invariant mass of four electrons] for 3 different values of mHiggs(We wouldnrsquot see all of these together)

q

q_ H

Z

Z

e+

e-

e+

e-

1 Find events consistent with above topology(four electrons)

2 Add together the fourelectron 4-vectors

3 Find the mass of the resultant4-vector ( mass of the Higgs)

mH=130mH=170

mH=150

background

Example (2) H γγbull No direct coupling

of H to photonbull However allowed at

loop levelbull Branching ratio

~ 10 -3

(at low mHiggs)bull Important at low

massbull Actually a very

clean way of looking for Higgsndash Small backgrounds

Production and decay of Higgsthrough lsquoforbiddenrsquo direct couplings

H γγ CMS simulation Physics TDR 2006H γγ CMS simulation Physics TDR 2006

γ

γ

H γγ

bull Simulation by CMS for different Higgs massesfor early LHC data (1 fb-1)

Higgs signalscaled up by factor 10

Invariant mass of the pair of photons

H γγ hellip backgrounds

ldquoIrreduciblerdquo2 real photons

ldquoReduciblerdquoeg fake photons

γ

gluon

q

q_

π0

γγ

Need v good calorimetersegmentationto separate these

ldquoBornrdquo ldquoBoxrdquo

Significance

H-gtZZ

Significance is a measureof the answer to the questionldquoWhat is the probabilitythat a backgroundfluctuation would producewhat I am seeingrdquo

5- means ldquoprobabilitythat background fluctuation does this is less than 28510-7 rdquo

5- is usually takenas benchmarkfor ldquodiscoveryrdquo

After discovery of Higgs

bull Measure Higgs massndash The remaining unconstrained parameter of the Standard Model

bull Measure Higgs couplings to fermions and vector bosonsndash All predicted by Standard Modelndash Check Higgs mechanism

bull Couplings very important since there may be more than one Higgs bosonndash Theories beyond the Standard Model (such as Supersymmetry)

predict multiple Higgs bosonsndash In such models the couplings would be modified

bull Do direct searches for further Higgs bosons

If no Higgs found

bull Arguably more exciting than finding Higgsbull Look at WW scattering process

ndash Look for whatever is ldquofixingrdquo the cross-sectionndash Eg exotic resonances

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Decay of the SM Higgs

bull Width becomes large as WW mode opensbull Branching ratios change rapidly as new

channels become kinematically accessible

Needle in a haystackhellip

Higgs production

QCD jet productionat high energy

Need to use signatures with small backgrounds- Leptons- High-mass resonances- Heavy quarksto avoid being overwhelmed

Need to use signatures with small backgrounds- Leptons- High-mass resonances- Heavy quarksto avoid being overwhelmed

Example 1 H ZZ

bull Only works when mHiggs gt~ 2MZ

bull When the Z decays to leptons there are small backgrounds

q

q_ H

Z

Z

e+

e-

e+

e-

H ZZ

H ZZ e+e- e+e-H ZZ e+e- e+e-

CMS

Electrons have track (green ) amp energy deposit (pink)

H ZZ e+e- e+e-

Plot shows simulated distributions of [invariant mass of four electrons] for 3 different values of mHiggs(We wouldnrsquot see all of these together)

q

q_ H

Z

Z

e+

e-

e+

e-

1 Find events consistent with above topology(four electrons)

2 Add together the fourelectron 4-vectors

3 Find the mass of the resultant4-vector ( mass of the Higgs)

mH=130mH=170

mH=150

background

Example (2) H γγbull No direct coupling

of H to photonbull However allowed at

loop levelbull Branching ratio

~ 10 -3

(at low mHiggs)bull Important at low

massbull Actually a very

clean way of looking for Higgsndash Small backgrounds

Production and decay of Higgsthrough lsquoforbiddenrsquo direct couplings

H γγ CMS simulation Physics TDR 2006H γγ CMS simulation Physics TDR 2006

γ

γ

H γγ

bull Simulation by CMS for different Higgs massesfor early LHC data (1 fb-1)

Higgs signalscaled up by factor 10

Invariant mass of the pair of photons

H γγ hellip backgrounds

ldquoIrreduciblerdquo2 real photons

ldquoReduciblerdquoeg fake photons

γ

gluon

q

q_

π0

γγ

Need v good calorimetersegmentationto separate these

ldquoBornrdquo ldquoBoxrdquo

Significance

H-gtZZ

Significance is a measureof the answer to the questionldquoWhat is the probabilitythat a backgroundfluctuation would producewhat I am seeingrdquo

5- means ldquoprobabilitythat background fluctuation does this is less than 28510-7 rdquo

5- is usually takenas benchmarkfor ldquodiscoveryrdquo

After discovery of Higgs

bull Measure Higgs massndash The remaining unconstrained parameter of the Standard Model

bull Measure Higgs couplings to fermions and vector bosonsndash All predicted by Standard Modelndash Check Higgs mechanism

bull Couplings very important since there may be more than one Higgs bosonndash Theories beyond the Standard Model (such as Supersymmetry)

predict multiple Higgs bosonsndash In such models the couplings would be modified

bull Do direct searches for further Higgs bosons

If no Higgs found

bull Arguably more exciting than finding Higgsbull Look at WW scattering process

ndash Look for whatever is ldquofixingrdquo the cross-sectionndash Eg exotic resonances

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Needle in a haystackhellip

Higgs production

QCD jet productionat high energy

Need to use signatures with small backgrounds- Leptons- High-mass resonances- Heavy quarksto avoid being overwhelmed

Need to use signatures with small backgrounds- Leptons- High-mass resonances- Heavy quarksto avoid being overwhelmed

Example 1 H ZZ

bull Only works when mHiggs gt~ 2MZ

bull When the Z decays to leptons there are small backgrounds

q

q_ H

Z

Z

e+

e-

e+

e-

H ZZ

H ZZ e+e- e+e-H ZZ e+e- e+e-

CMS

Electrons have track (green ) amp energy deposit (pink)

H ZZ e+e- e+e-

Plot shows simulated distributions of [invariant mass of four electrons] for 3 different values of mHiggs(We wouldnrsquot see all of these together)

q

q_ H

Z

Z

e+

e-

e+

e-

1 Find events consistent with above topology(four electrons)

2 Add together the fourelectron 4-vectors

3 Find the mass of the resultant4-vector ( mass of the Higgs)

mH=130mH=170

mH=150

background

Example (2) H γγbull No direct coupling

of H to photonbull However allowed at

loop levelbull Branching ratio

~ 10 -3

(at low mHiggs)bull Important at low

massbull Actually a very

clean way of looking for Higgsndash Small backgrounds

Production and decay of Higgsthrough lsquoforbiddenrsquo direct couplings

H γγ CMS simulation Physics TDR 2006H γγ CMS simulation Physics TDR 2006

γ

γ

H γγ

bull Simulation by CMS for different Higgs massesfor early LHC data (1 fb-1)

Higgs signalscaled up by factor 10

Invariant mass of the pair of photons

H γγ hellip backgrounds

ldquoIrreduciblerdquo2 real photons

ldquoReduciblerdquoeg fake photons

γ

gluon

q

q_

π0

γγ

Need v good calorimetersegmentationto separate these

ldquoBornrdquo ldquoBoxrdquo

Significance

H-gtZZ

Significance is a measureof the answer to the questionldquoWhat is the probabilitythat a backgroundfluctuation would producewhat I am seeingrdquo

5- means ldquoprobabilitythat background fluctuation does this is less than 28510-7 rdquo

5- is usually takenas benchmarkfor ldquodiscoveryrdquo

After discovery of Higgs

bull Measure Higgs massndash The remaining unconstrained parameter of the Standard Model

bull Measure Higgs couplings to fermions and vector bosonsndash All predicted by Standard Modelndash Check Higgs mechanism

bull Couplings very important since there may be more than one Higgs bosonndash Theories beyond the Standard Model (such as Supersymmetry)

predict multiple Higgs bosonsndash In such models the couplings would be modified

bull Do direct searches for further Higgs bosons

If no Higgs found

bull Arguably more exciting than finding Higgsbull Look at WW scattering process

ndash Look for whatever is ldquofixingrdquo the cross-sectionndash Eg exotic resonances

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Example 1 H ZZ

bull Only works when mHiggs gt~ 2MZ

bull When the Z decays to leptons there are small backgrounds

q

q_ H

Z

Z

e+

e-

e+

e-

H ZZ

H ZZ e+e- e+e-H ZZ e+e- e+e-

CMS

Electrons have track (green ) amp energy deposit (pink)

H ZZ e+e- e+e-

Plot shows simulated distributions of [invariant mass of four electrons] for 3 different values of mHiggs(We wouldnrsquot see all of these together)

q

q_ H

Z

Z

e+

e-

e+

e-

1 Find events consistent with above topology(four electrons)

2 Add together the fourelectron 4-vectors

3 Find the mass of the resultant4-vector ( mass of the Higgs)

mH=130mH=170

mH=150

background

Example (2) H γγbull No direct coupling

of H to photonbull However allowed at

loop levelbull Branching ratio

~ 10 -3

(at low mHiggs)bull Important at low

massbull Actually a very

clean way of looking for Higgsndash Small backgrounds

Production and decay of Higgsthrough lsquoforbiddenrsquo direct couplings

H γγ CMS simulation Physics TDR 2006H γγ CMS simulation Physics TDR 2006

γ

γ

H γγ

bull Simulation by CMS for different Higgs massesfor early LHC data (1 fb-1)

Higgs signalscaled up by factor 10

Invariant mass of the pair of photons

H γγ hellip backgrounds

ldquoIrreduciblerdquo2 real photons

ldquoReduciblerdquoeg fake photons

γ

gluon

q

q_

π0

γγ

Need v good calorimetersegmentationto separate these

ldquoBornrdquo ldquoBoxrdquo

Significance

H-gtZZ

Significance is a measureof the answer to the questionldquoWhat is the probabilitythat a backgroundfluctuation would producewhat I am seeingrdquo

5- means ldquoprobabilitythat background fluctuation does this is less than 28510-7 rdquo

5- is usually takenas benchmarkfor ldquodiscoveryrdquo

After discovery of Higgs

bull Measure Higgs massndash The remaining unconstrained parameter of the Standard Model

bull Measure Higgs couplings to fermions and vector bosonsndash All predicted by Standard Modelndash Check Higgs mechanism

bull Couplings very important since there may be more than one Higgs bosonndash Theories beyond the Standard Model (such as Supersymmetry)

predict multiple Higgs bosonsndash In such models the couplings would be modified

bull Do direct searches for further Higgs bosons

If no Higgs found

bull Arguably more exciting than finding Higgsbull Look at WW scattering process

ndash Look for whatever is ldquofixingrdquo the cross-sectionndash Eg exotic resonances

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

H ZZ

H ZZ e+e- e+e-H ZZ e+e- e+e-

CMS

Electrons have track (green ) amp energy deposit (pink)

H ZZ e+e- e+e-

Plot shows simulated distributions of [invariant mass of four electrons] for 3 different values of mHiggs(We wouldnrsquot see all of these together)

q

q_ H

Z

Z

e+

e-

e+

e-

1 Find events consistent with above topology(four electrons)

2 Add together the fourelectron 4-vectors

3 Find the mass of the resultant4-vector ( mass of the Higgs)

mH=130mH=170

mH=150

background

Example (2) H γγbull No direct coupling

of H to photonbull However allowed at

loop levelbull Branching ratio

~ 10 -3

(at low mHiggs)bull Important at low

massbull Actually a very

clean way of looking for Higgsndash Small backgrounds

Production and decay of Higgsthrough lsquoforbiddenrsquo direct couplings

H γγ CMS simulation Physics TDR 2006H γγ CMS simulation Physics TDR 2006

γ

γ

H γγ

bull Simulation by CMS for different Higgs massesfor early LHC data (1 fb-1)

Higgs signalscaled up by factor 10

Invariant mass of the pair of photons

H γγ hellip backgrounds

ldquoIrreduciblerdquo2 real photons

ldquoReduciblerdquoeg fake photons

γ

gluon

q

q_

π0

γγ

Need v good calorimetersegmentationto separate these

ldquoBornrdquo ldquoBoxrdquo

Significance

H-gtZZ

Significance is a measureof the answer to the questionldquoWhat is the probabilitythat a backgroundfluctuation would producewhat I am seeingrdquo

5- means ldquoprobabilitythat background fluctuation does this is less than 28510-7 rdquo

5- is usually takenas benchmarkfor ldquodiscoveryrdquo

After discovery of Higgs

bull Measure Higgs massndash The remaining unconstrained parameter of the Standard Model

bull Measure Higgs couplings to fermions and vector bosonsndash All predicted by Standard Modelndash Check Higgs mechanism

bull Couplings very important since there may be more than one Higgs bosonndash Theories beyond the Standard Model (such as Supersymmetry)

predict multiple Higgs bosonsndash In such models the couplings would be modified

bull Do direct searches for further Higgs bosons

If no Higgs found

bull Arguably more exciting than finding Higgsbull Look at WW scattering process

ndash Look for whatever is ldquofixingrdquo the cross-sectionndash Eg exotic resonances

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

H ZZ e+e- e+e-

Plot shows simulated distributions of [invariant mass of four electrons] for 3 different values of mHiggs(We wouldnrsquot see all of these together)

q

q_ H

Z

Z

e+

e-

e+

e-

1 Find events consistent with above topology(four electrons)

2 Add together the fourelectron 4-vectors

3 Find the mass of the resultant4-vector ( mass of the Higgs)

mH=130mH=170

mH=150

background

Example (2) H γγbull No direct coupling

of H to photonbull However allowed at

loop levelbull Branching ratio

~ 10 -3

(at low mHiggs)bull Important at low

massbull Actually a very

clean way of looking for Higgsndash Small backgrounds

Production and decay of Higgsthrough lsquoforbiddenrsquo direct couplings

H γγ CMS simulation Physics TDR 2006H γγ CMS simulation Physics TDR 2006

γ

γ

H γγ

bull Simulation by CMS for different Higgs massesfor early LHC data (1 fb-1)

Higgs signalscaled up by factor 10

Invariant mass of the pair of photons

H γγ hellip backgrounds

ldquoIrreduciblerdquo2 real photons

ldquoReduciblerdquoeg fake photons

γ

gluon

q

q_

π0

γγ

Need v good calorimetersegmentationto separate these

ldquoBornrdquo ldquoBoxrdquo

Significance

H-gtZZ

Significance is a measureof the answer to the questionldquoWhat is the probabilitythat a backgroundfluctuation would producewhat I am seeingrdquo

5- means ldquoprobabilitythat background fluctuation does this is less than 28510-7 rdquo

5- is usually takenas benchmarkfor ldquodiscoveryrdquo

After discovery of Higgs

bull Measure Higgs massndash The remaining unconstrained parameter of the Standard Model

bull Measure Higgs couplings to fermions and vector bosonsndash All predicted by Standard Modelndash Check Higgs mechanism

bull Couplings very important since there may be more than one Higgs bosonndash Theories beyond the Standard Model (such as Supersymmetry)

predict multiple Higgs bosonsndash In such models the couplings would be modified

bull Do direct searches for further Higgs bosons

If no Higgs found

bull Arguably more exciting than finding Higgsbull Look at WW scattering process

ndash Look for whatever is ldquofixingrdquo the cross-sectionndash Eg exotic resonances

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Example (2) H γγbull No direct coupling

of H to photonbull However allowed at

loop levelbull Branching ratio

~ 10 -3

(at low mHiggs)bull Important at low

massbull Actually a very

clean way of looking for Higgsndash Small backgrounds

Production and decay of Higgsthrough lsquoforbiddenrsquo direct couplings

H γγ CMS simulation Physics TDR 2006H γγ CMS simulation Physics TDR 2006

γ

γ

H γγ

bull Simulation by CMS for different Higgs massesfor early LHC data (1 fb-1)

Higgs signalscaled up by factor 10

Invariant mass of the pair of photons

H γγ hellip backgrounds

ldquoIrreduciblerdquo2 real photons

ldquoReduciblerdquoeg fake photons

γ

gluon

q

q_

π0

γγ

Need v good calorimetersegmentationto separate these

ldquoBornrdquo ldquoBoxrdquo

Significance

H-gtZZ

Significance is a measureof the answer to the questionldquoWhat is the probabilitythat a backgroundfluctuation would producewhat I am seeingrdquo

5- means ldquoprobabilitythat background fluctuation does this is less than 28510-7 rdquo

5- is usually takenas benchmarkfor ldquodiscoveryrdquo

After discovery of Higgs

bull Measure Higgs massndash The remaining unconstrained parameter of the Standard Model

bull Measure Higgs couplings to fermions and vector bosonsndash All predicted by Standard Modelndash Check Higgs mechanism

bull Couplings very important since there may be more than one Higgs bosonndash Theories beyond the Standard Model (such as Supersymmetry)

predict multiple Higgs bosonsndash In such models the couplings would be modified

bull Do direct searches for further Higgs bosons

If no Higgs found

bull Arguably more exciting than finding Higgsbull Look at WW scattering process

ndash Look for whatever is ldquofixingrdquo the cross-sectionndash Eg exotic resonances

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

H γγ CMS simulation Physics TDR 2006H γγ CMS simulation Physics TDR 2006

γ

γ

H γγ

bull Simulation by CMS for different Higgs massesfor early LHC data (1 fb-1)

Higgs signalscaled up by factor 10

Invariant mass of the pair of photons

H γγ hellip backgrounds

ldquoIrreduciblerdquo2 real photons

ldquoReduciblerdquoeg fake photons

γ

gluon

q

q_

π0

γγ

Need v good calorimetersegmentationto separate these

ldquoBornrdquo ldquoBoxrdquo

Significance

H-gtZZ

Significance is a measureof the answer to the questionldquoWhat is the probabilitythat a backgroundfluctuation would producewhat I am seeingrdquo

5- means ldquoprobabilitythat background fluctuation does this is less than 28510-7 rdquo

5- is usually takenas benchmarkfor ldquodiscoveryrdquo

After discovery of Higgs

bull Measure Higgs massndash The remaining unconstrained parameter of the Standard Model

bull Measure Higgs couplings to fermions and vector bosonsndash All predicted by Standard Modelndash Check Higgs mechanism

bull Couplings very important since there may be more than one Higgs bosonndash Theories beyond the Standard Model (such as Supersymmetry)

predict multiple Higgs bosonsndash In such models the couplings would be modified

bull Do direct searches for further Higgs bosons

If no Higgs found

bull Arguably more exciting than finding Higgsbull Look at WW scattering process

ndash Look for whatever is ldquofixingrdquo the cross-sectionndash Eg exotic resonances

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

H γγ

bull Simulation by CMS for different Higgs massesfor early LHC data (1 fb-1)

Higgs signalscaled up by factor 10

Invariant mass of the pair of photons

H γγ hellip backgrounds

ldquoIrreduciblerdquo2 real photons

ldquoReduciblerdquoeg fake photons

γ

gluon

q

q_

π0

γγ

Need v good calorimetersegmentationto separate these

ldquoBornrdquo ldquoBoxrdquo

Significance

H-gtZZ

Significance is a measureof the answer to the questionldquoWhat is the probabilitythat a backgroundfluctuation would producewhat I am seeingrdquo

5- means ldquoprobabilitythat background fluctuation does this is less than 28510-7 rdquo

5- is usually takenas benchmarkfor ldquodiscoveryrdquo

After discovery of Higgs

bull Measure Higgs massndash The remaining unconstrained parameter of the Standard Model

bull Measure Higgs couplings to fermions and vector bosonsndash All predicted by Standard Modelndash Check Higgs mechanism

bull Couplings very important since there may be more than one Higgs bosonndash Theories beyond the Standard Model (such as Supersymmetry)

predict multiple Higgs bosonsndash In such models the couplings would be modified

bull Do direct searches for further Higgs bosons

If no Higgs found

bull Arguably more exciting than finding Higgsbull Look at WW scattering process

ndash Look for whatever is ldquofixingrdquo the cross-sectionndash Eg exotic resonances

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

H γγ hellip backgrounds

ldquoIrreduciblerdquo2 real photons

ldquoReduciblerdquoeg fake photons

γ

gluon

q

q_

π0

γγ

Need v good calorimetersegmentationto separate these

ldquoBornrdquo ldquoBoxrdquo

Significance

H-gtZZ

Significance is a measureof the answer to the questionldquoWhat is the probabilitythat a backgroundfluctuation would producewhat I am seeingrdquo

5- means ldquoprobabilitythat background fluctuation does this is less than 28510-7 rdquo

5- is usually takenas benchmarkfor ldquodiscoveryrdquo

After discovery of Higgs

bull Measure Higgs massndash The remaining unconstrained parameter of the Standard Model

bull Measure Higgs couplings to fermions and vector bosonsndash All predicted by Standard Modelndash Check Higgs mechanism

bull Couplings very important since there may be more than one Higgs bosonndash Theories beyond the Standard Model (such as Supersymmetry)

predict multiple Higgs bosonsndash In such models the couplings would be modified

bull Do direct searches for further Higgs bosons

If no Higgs found

bull Arguably more exciting than finding Higgsbull Look at WW scattering process

ndash Look for whatever is ldquofixingrdquo the cross-sectionndash Eg exotic resonances

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Significance

H-gtZZ

Significance is a measureof the answer to the questionldquoWhat is the probabilitythat a backgroundfluctuation would producewhat I am seeingrdquo

5- means ldquoprobabilitythat background fluctuation does this is less than 28510-7 rdquo

5- is usually takenas benchmarkfor ldquodiscoveryrdquo

After discovery of Higgs

bull Measure Higgs massndash The remaining unconstrained parameter of the Standard Model

bull Measure Higgs couplings to fermions and vector bosonsndash All predicted by Standard Modelndash Check Higgs mechanism

bull Couplings very important since there may be more than one Higgs bosonndash Theories beyond the Standard Model (such as Supersymmetry)

predict multiple Higgs bosonsndash In such models the couplings would be modified

bull Do direct searches for further Higgs bosons

If no Higgs found

bull Arguably more exciting than finding Higgsbull Look at WW scattering process

ndash Look for whatever is ldquofixingrdquo the cross-sectionndash Eg exotic resonances

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

After discovery of Higgs

bull Measure Higgs massndash The remaining unconstrained parameter of the Standard Model

bull Measure Higgs couplings to fermions and vector bosonsndash All predicted by Standard Modelndash Check Higgs mechanism

bull Couplings very important since there may be more than one Higgs bosonndash Theories beyond the Standard Model (such as Supersymmetry)

predict multiple Higgs bosonsndash In such models the couplings would be modified

bull Do direct searches for further Higgs bosons

If no Higgs found

bull Arguably more exciting than finding Higgsbull Look at WW scattering process

ndash Look for whatever is ldquofixingrdquo the cross-sectionndash Eg exotic resonances

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

If no Higgs found

bull Arguably more exciting than finding Higgsbull Look at WW scattering process

ndash Look for whatever is ldquofixingrdquo the cross-sectionndash Eg exotic resonances

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

What is supersymmetry

bull Nature permits only particular types of symmetryndash Space amp time

bull Lorentz transformsbull Rotations and translations

ndash Gauge symmetrybull Such as Standard Model

force symmetriesbull SU(3)c x SU(2)L x U(1)

ndash Supersymmetrybull Anti-commuting

(Fermionic) generators bull Changes Fermions into

Bosons and vice-versa

bull Consequencesndash Supersymmetric theory has

a Boson for every Fermion and vice-versa

bull Doubles the particle contentndash Partners to Standard Model

particles not yet observed

Examples of Supersymmetric partner-states

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Extended higgs sector 2 cplx doublets 8-3 = 5 Higgs bosons

(S)ParticlesStandard

ModelSupersymmetric

partners

quarks (LampR)leptons (LampR) neutrinos (Lamp)

squarks (LampR)sleptons (LampR)sneutrinos (Lamp)

Z0

Wplusmn

gluon

BW0

h0

H0

A0

Hplusmn

H0

Hplusmn

4 x neutralino

2 x chargino

AfterMixing

gluino

Spin-12

Spin-1

Spin-0

Spin-12

Spin-0

BinoWino0

Winoplusmn

gluino

~

~

(Higgsinos)

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Why Supersymmetrybull Higgs mass

ndash Quantum corrections to mH

ndash Would make ldquonaturalrdquo mass near cut-off (Unification or Planck scale)

ndash But we know mH lt~ 1 TeVndash mH = mH bare + mH

ndash Severe fine tuning required between two very big numbers

bull Enter Supersymmetry (SUSY)ndash Scalar partner of quarks also

provide quantum correctionsndash Factor of -1 from Feynman rulesndash Same coupling λndash Quadratic corrections cancelndash mH now natrually at electroweak

scale

top

Δm2(h) Λ2cutoff

higgs higgs

λλ

stop

higgs higgs

λ λ

Quantum correction to mHiggs

Cancelling correction to mHiggs

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Further advantagesbull Lightest SUSY

particle isndash Lightndash Weakly interacting ndash Stablendash Massive

bull Good dark matter candidate

bull Predicts gauge unificationndash Extra particles modify

running of couplingsndash Step towards ldquohigher

thingsrdquo

SM

+SUSY

Log10 (μ GeV)

Log10 (μ GeV)

miss

Hit

1α 1α

Big Bang relic abundance calculations are in good agreement with WMAP microwave background observations in regions of SUSY parameter space

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

R-paritybull Multiplicative discrete quantum

numberbull RP = (-1)2s+3B+L

ndash S=spin B=baryon number L=lepton number

bull Standard Model particles have RP = +1

bull SUSY Model particles have RP = -1

bull If RP is conserved then SUSY particles must be pair-produced

bull If RP is conserved then the Lightest Supersymmetric Particle (LSP) is stable

Example of a Feynmandiagram for proton decaywhich is allowed if the RP-violating couplings (λ) are not zero

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

How is SUSY brokenbull Direct breaking in

visible sector not possiblendash Would require

squarkssleptons with mass lt mSM

ndash Not observedbull Must be strongly

broken ldquoelsewhererdquo and then mediatedndash Soft breaking terms

enter in visible sectorndash (gt100 parameters)

Stronglybrokensector

Weakcoupling(mediation)

Soft SUSY-breaking termsenter lagrangianin visible sector

Various models offer different mediation egGauge ldquoGMSBrdquoGravity ldquomSUGRArdquo (supergravity)

Anomaly ldquoAMSBrdquo

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Sparticle Interactions

bull Interactions amp couplings same as SM partners

bull 2 SUSY legs for RP conservation

Largely partnerof W0 boson

Largely partnerof W0 boson

Q Does the gluino couple tothe quarkthe sleptonthe photino

Q Does the gluino couple tothe quarkthe sleptonthe photino

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

General featuresMassGeV

ldquotypicalrdquo susy spectrum(mSUGRA)

bull Complicated cascade decaysndash Many

intermediates

bull Typical signalndash Jets

bull Squarks and Gluinos

ndash Leptonsbull Sleptons and weak

gauginos

ndash Missing energybull Undetected

Lightest Susy Particle

Production dominatedby squarks and gluinos

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

The ldquoreal thingrdquo(a simulation ofhellip)

bull Two high-energy jets of particlesndash Visible decay

productsbull ldquoMissingrdquo

momentumndash From two

invisible particles

ndash these are the invisible Dark Matter guys

Proton beams perpendicular to screenProton beams perpendicular to screen

Invisibleparticles

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Standard Model backgrounds measure from LHC DATA

bull Example backgroundto ldquo4 jets + missing energyrdquondash Measure background in control regionndash Extrapolate to signal regionndash Look for excess in signal region

Measure in Z -gt μμ

Use in Z -gt νν R Z

B Estimated

R Z

B Estimated

μ μ

With SUSY

Missing PT GeV

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Constraining SUSY massesbull Mass constraintsbull Invariant masses in pairs

ndash Missing energyndash Kinematic edges

Observable Depends on

Limits depend on angles betweensparticle decays

Frequently-studieddecay chain

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Mass determination

Measureedges

Variety of edgesvariables

Try variousmasses in equations

CG Lester

bull Narrow bands in ΔMbull Wider in mass scalebull Improve using cross- section information

These measurements can tell us about SUSY breaking

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Other things to do with SUSY

bull Measure the sparticle spins ndash ldquoproverdquo that it is really supersymmetric

partners we are seeing

bull Measuring the couplings amp mixingsndash Use to ldquopredictrdquo Dark Matter relic density

bull Find the extra Higgs bosonsndash Recall that SUSY predicts 5 Higgs bosonsndash Now we want to find H0 h0 A0 Hplusmn

ndash Also measure their couplings CP hellip

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Standard Model Physics

bull The ATLAS and CMS experiments also potentially can measurendash Top massndash W massndash Rare B-meson decay ratesndash Jet physics

bull To much higher precision that is currently achievablendash Large number of eg top quarks

producedndash Small statistical errorsndash Systematic errors (such as jet

energy scale determination) limiting

Mass of hadronic top

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Other things to look forhellip

bull Leptoquarksndash Motivated by Grand Unified Theoriesndash Carry lepton and baryon numberndash Eg LQ bμ

bull New heavy quarksndash Predicted by some non-SM Higgs theories

bull New heavy gauge bosonsndash Indications of new symmetry groups

bull Extra dimensionsndash Large variety of models on the market

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

Extra dimensions models

bull Motivated by need for ED in string theory and m-theoryndash Logical a possibility for a LHC discovery

bull Different modelshellipndash Which particles are localised where (bulkbrane)ndash Form of space-time metric (flatwarped)ndash Geometry and size of extra dimensions

bull hellipmake different predictionsndash Kalazua-Klein resonances of SM particlesndash Graviton statesndash Stringy resonancesndash Effects of strong gravity (micro Black Holes)ndash Energy loss into extra dimensions

More informationhttpeps2003physikrwth-aachendedatatalksparallel09StringTheory09Vacavantppt

General sources

bull Higgs at the LHC talk by Zeppenfeld httpwhepp9iopbresintalkszeppenfeld_WHEPP9pdf

bull Physics at the LHC Higgs talk by HarlanderhttpnewtonftjagheduplphysLHC

bull ATLAS physics Technical Design Report (TDR)httpatlaswebcernchAtlasGROUPSPHYSICSTDRaccesshtml (1999)

bull CMS physics Technical Design Report (TDR)httpcmsdoccernchcmscpttdr (2006)

bull Supersymmetry httparxivorgabshep-ph9709356

Constraints on mHiggs

Scale at which new physics enters

Unstable vacuum

No perturbative unitarity

Producing a Higgs LHC

bull Higgs couplings massndash Direct eg u-ubar H

very small cross-sectionbull Dominant production via

vertices coupling Higgs to heavy quarks or WZ bosons

bull Higgs couplings massndash Direct eg u-ubar H

very small cross-sectionbull Dominant production via

vertices coupling Higgs to heavy quarks or WZ bosons

top

H

g

g

WZH

q

q_

top

H

g

gWZ

H

q

q_

Higgsrsquo mechanismbull Add a complex scalar field

ndash In fact he adds 2 real scalar fields

(fermion part of L now ignored)

This is gauge invariant when the scalars have covariant derivatives

Now if the potential V has a degenerate minimum at φne0 we get interesting consequenceshellip

NB scalar field must couple to gauge field likethis for the Higgsmechanism to work

NB scalar field must couple to gauge field likethis for the Higgsmechanism to work

mSUGRA ndash ldquosuper gravityrdquobull AKA cMSSMbull Gravity mediated SUSY

breakingndash Flavour-blind (no FCNCs)

bull Strong expt limitsndash Unification at high scales

bull Reduce SUSY parameter spacendash Common scalar mass M0

bull squarks sleptonsndash Common fermionic mass Mfrac12

bull Gauginosndash Common trilinear couplings A0

bull Susy equivalent of Yukawas

Programs includeeg ISASUSYSOFTSUSY

1016 GeV

EW scale

Iterate usingRenormalisationGroupEquations

Unification of couplings

Correct MZ MW hellip

Other suggestions for SUSY breaking

bull Gauge mediationndash Gauge (SM) fields in extra dimensions mediate SUSY breaking

bull Automatic diagonal couplings no EWSB

ndash No direct gravitino mass until Mpl

bull Lightest SUSY particle is gravitinobull Next-to-lightest can be long-lived (eg stau or neutralino)

bull Anomaly mediationndash Sequestered sector (via extra dimension)

bull Loop diagram in scalar part of graviton mediates SUSY breakingbull Dominates in absence of direct couplings

ndash Leads to SUSY breaking RGE β-functionsbull Neutral Wino LSPbull Charged Wino near-degenerate with LSP lifetime bull Interesting track signatures

Not exhaustive

Producing exotics

Time

standard

exotic

Time

standard

exotic

Time

standard

exotics

Time

standardexotics

bull If exotics can be produced singly they can decayndash No good for

Dark Matter candidate

bull If they can only be pair-produced they are stablendash Only

disappear on collision (rare)

Require an even number of exotic legs tofrom blobs(Conserved multiplicative quantum number)

If we want a good dark matter candidate

Require an even number of exotic legs tofrom blobs(Conserved multiplicative quantum number)

If we want a good dark matter candidate

No RP

With RP

How do they then behave

bull Events build from blobs with 2 ldquoexotic legsrdquo

bull A pair of cascade decays results

bull Complicated end result

bull Events build from blobs with 2 ldquoexotic legsrdquo

bull A pair of cascade decays results

bull Complicated end result

Time

standard

2 exotics

Production part

Time

standard

heavyexotic lighter

exotic

Decay part Time

Complete ldquoeventrdquo

= exotic= standard

• LHC Physics
• This morningrsquos stuffhellip
• Physics at TeV-scale
• Higgs mechanism - history
• Higgs mechanism why needed
• Pictorial representation
• Higgs field ldquoeats Goldstone bosonrdquo
• Constraints on the Higgs mass
• Perturbative limit
• Indirect Higgs bounds LEP Electroweak data
• Direct bounds Higgs searches LEP
• Higgs-Hunter Situation Report
• Slide 13
• The Large Hadron Collider
• General Purpose Detectors
• Definitions
• Making particles in hadron colliders
• LHCb
• LHCb Physics
• Slide 20
• ALICE
• Slide 22
• Couplings of the SM Higgs
• Producing a Higgs
• Production cross-sections
• Decay of the SM Higgs
• Slide 27
• Example 1 H ZZ
• H ZZ
• H ZZ e+e- e+e-
• Example (2) H γγ
• Slide 32
• H γγ
• H γγ hellip backgrounds
• Significance
• After discovery of Higgs
• If no Higgs found
• Slide 39
• What is supersymmetry
• (S)Particles
• Why Supersymmetry
• Further advantages
• R-parity
• How is SUSY broken
• Sparticle Interactions
• Slide 47
• General features
• The ldquoreal thingrdquo (a simulation ofhellip)
• Standard Model backgrounds measure from LHC DATA
• Constraining SUSY masses
• Mass determination
• Other things to do with SUSY
• Standard Model Physics
• Other things to look forhellip
• Extra dimensions models
• Slide 57
• General sources
• Constraints on mHiggs
• Producing a Higgs LHC
• Higgsrsquo mechanism
• mSUGRA ndash ldquosuper gravityrdquo
• Other suggestions for SUSY breaking
• Producing exotics
• How do they then behave

Producing a Higgs LHC

bull Higgs couplings massndash Direct eg u-ubar H

very small cross-sectionbull Dominant production via

vertices coupling Higgs to heavy quarks or WZ bosons

bull Higgs couplings massndash Direct eg u-ubar H

very small cross-sectionbull Dominant production via

vertices coupling Higgs to heavy quarks or WZ bosons

top

H

g

g

WZH

q

q_

top

H

g

gWZ

H

q

q_

Higgsrsquo mechanismbull Add a complex scalar field

ndash In fact he adds 2 real scalar fields

(fermion part of L now ignored)

This is gauge invariant when the scalars have covariant derivatives

Now if the potential V has a degenerate minimum at φne0 we get interesting consequenceshellip

NB scalar field must couple to gauge field likethis for the Higgsmechanism to work

NB scalar field must couple to gauge field likethis for the Higgsmechanism to work

mSUGRA ndash ldquosuper gravityrdquobull AKA cMSSMbull Gravity mediated SUSY

breakingndash Flavour-blind (no FCNCs)

bull Strong expt limitsndash Unification at high scales

bull Reduce SUSY parameter spacendash Common scalar mass M0

bull squarks sleptonsndash Common fermionic mass Mfrac12

bull Gauginosndash Common trilinear couplings A0

bull Susy equivalent of Yukawas

Programs includeeg ISASUSYSOFTSUSY

1016 GeV

EW scale

Iterate usingRenormalisationGroupEquations

Unification of couplings

Correct MZ MW hellip

Other suggestions for SUSY breaking

bull Gauge mediationndash Gauge (SM) fields in extra dimensions mediate SUSY breaking

bull Automatic diagonal couplings no EWSB

ndash No direct gravitino mass until Mpl

bull Lightest SUSY particle is gravitinobull Next-to-lightest can be long-lived (eg stau or neutralino)

bull Anomaly mediationndash Sequestered sector (via extra dimension)

bull Loop diagram in scalar part of graviton mediates SUSY breakingbull Dominates in absence of direct couplings

ndash Leads to SUSY breaking RGE β-functionsbull Neutral Wino LSPbull Charged Wino near-degenerate with LSP lifetime bull Interesting track signatures

Not exhaustive

Producing exotics

Time

standard

exotic

Time

standard

exotic

Time

standard

exotics

Time

standardexotics

bull If exotics can be produced singly they can decayndash No good for

Dark Matter candidate

bull If they can only be pair-produced they are stablendash Only

disappear on collision (rare)

Require an even number of exotic legs tofrom blobs(Conserved multiplicative quantum number)

If we want a good dark matter candidate

Require an even number of exotic legs tofrom blobs(Conserved multiplicative quantum number)

If we want a good dark matter candidate

No RP

With RP

How do they then behave

bull Events build from blobs with 2 ldquoexotic legsrdquo

bull A pair of cascade decays results

bull Complicated end result

bull Events build from blobs with 2 ldquoexotic legsrdquo

bull A pair of cascade decays results

bull Complicated end result

Time

standard

2 exotics

Production part

Time

standard

heavyexotic lighter

exotic

Decay part Time

Complete ldquoeventrdquo

= exotic= standard

• LHC Physics
• This morningrsquos stuffhellip
• Physics at TeV-scale
• Higgs mechanism - history
• Higgs mechanism why needed
• Pictorial representation
• Higgs field ldquoeats Goldstone bosonrdquo
• Constraints on the Higgs mass
• Perturbative limit
• Indirect Higgs bounds LEP Electroweak data
• Direct bounds Higgs searches LEP
• Higgs-Hunter Situation Report
• Slide 13
• The Large Hadron Collider
• General Purpose Detectors
• Definitions
• Making particles in hadron colliders
• LHCb
• LHCb Physics
• Slide 20
• ALICE
• Slide 22
• Couplings of the SM Higgs
• Producing a Higgs
• Production cross-sections
• Decay of the SM Higgs
• Slide 27
• Example 1 H ZZ
• H ZZ
• H ZZ e+e- e+e-
• Example (2) H γγ
• Slide 32
• H γγ
• H γγ hellip backgrounds
• Significance
• After discovery of Higgs
• If no Higgs found
• Slide 39
• What is supersymmetry
• (S)Particles
• Why Supersymmetry
• Further advantages
• R-parity
• How is SUSY broken
• Sparticle Interactions
• Slide 47
• General features
• The ldquoreal thingrdquo (a simulation ofhellip)
• Standard Model backgrounds measure from LHC DATA
• Constraining SUSY masses
• Mass determination
• Other things to do with SUSY
• Standard Model Physics
• Other things to look forhellip
• Extra dimensions models
• Slide 57
• General sources
• Constraints on mHiggs
• Producing a Higgs LHC
• Higgsrsquo mechanism
• mSUGRA ndash ldquosuper gravityrdquo
• Other suggestions for SUSY breaking
• Producing exotics
• How do they then behave

Higgsrsquo mechanismbull Add a complex scalar field

ndash In fact he adds 2 real scalar fields

(fermion part of L now ignored)

This is gauge invariant when the scalars have covariant derivatives

Now if the potential V has a degenerate minimum at φne0 we get interesting consequenceshellip

NB scalar field must couple to gauge field likethis for the Higgsmechanism to work

NB scalar field must couple to gauge field likethis for the Higgsmechanism to work

mSUGRA ndash ldquosuper gravityrdquobull AKA cMSSMbull Gravity mediated SUSY

breakingndash Flavour-blind (no FCNCs)

bull Strong expt limitsndash Unification at high scales

bull Reduce SUSY parameter spacendash Common scalar mass M0

bull squarks sleptonsndash Common fermionic mass Mfrac12

bull Gauginosndash Common trilinear couplings A0

bull Susy equivalent of Yukawas

Programs includeeg ISASUSYSOFTSUSY

1016 GeV

EW scale

Iterate usingRenormalisationGroupEquations

Unification of couplings

Correct MZ MW hellip

Other suggestions for SUSY breaking

bull Gauge mediationndash Gauge (SM) fields in extra dimensions mediate SUSY breaking

bull Automatic diagonal couplings no EWSB

ndash No direct gravitino mass until Mpl

bull Lightest SUSY particle is gravitinobull Next-to-lightest can be long-lived (eg stau or neutralino)

bull Anomaly mediationndash Sequestered sector (via extra dimension)

bull Loop diagram in scalar part of graviton mediates SUSY breakingbull Dominates in absence of direct couplings

ndash Leads to SUSY breaking RGE β-functionsbull Neutral Wino LSPbull Charged Wino near-degenerate with LSP lifetime bull Interesting track signatures

Not exhaustive

Producing exotics

Time

standard

exotic

Time

standard

exotic

Time

standard

exotics

Time

standardexotics

bull If exotics can be produced singly they can decayndash No good for

Dark Matter candidate

bull If they can only be pair-produced they are stablendash Only

disappear on collision (rare)

Require an even number of exotic legs tofrom blobs(Conserved multiplicative quantum number)

If we want a good dark matter candidate

Require an even number of exotic legs tofrom blobs(Conserved multiplicative quantum number)

If we want a good dark matter candidate

No RP

With RP

How do they then behave

bull Events build from blobs with 2 ldquoexotic legsrdquo

bull A pair of cascade decays results

bull Complicated end result

bull Events build from blobs with 2 ldquoexotic legsrdquo

bull A pair of cascade decays results

bull Complicated end result

Time

standard

2 exotics

Production part

Time

standard

heavyexotic lighter

exotic

Decay part Time

Complete ldquoeventrdquo

= exotic= standard

• LHC Physics
• This morningrsquos stuffhellip
• Physics at TeV-scale
• Higgs mechanism - history
• Higgs mechanism why needed
• Pictorial representation
• Higgs field ldquoeats Goldstone bosonrdquo
• Constraints on the Higgs mass
• Perturbative limit
• Indirect Higgs bounds LEP Electroweak data
• Direct bounds Higgs searches LEP
• Higgs-Hunter Situation Report
• Slide 13
• The Large Hadron Collider
• General Purpose Detectors
• Definitions
• Making particles in hadron colliders
• LHCb
• LHCb Physics
• Slide 20
• ALICE
• Slide 22
• Couplings of the SM Higgs
• Producing a Higgs
• Production cross-sections
• Decay of the SM Higgs
• Slide 27
• Example 1 H ZZ
• H ZZ
• H ZZ e+e- e+e-
• Example (2) H γγ
• Slide 32
• H γγ
• H γγ hellip backgrounds
• Significance
• After discovery of Higgs
• If no Higgs found
• Slide 39
• What is supersymmetry
• (S)Particles
• Why Supersymmetry
• Further advantages
• R-parity
• How is SUSY broken
• Sparticle Interactions
• Slide 47
• General features
• The ldquoreal thingrdquo (a simulation ofhellip)
• Standard Model backgrounds measure from LHC DATA
• Constraining SUSY masses
• Mass determination
• Other things to do with SUSY
• Standard Model Physics
• Other things to look forhellip
• Extra dimensions models
• Slide 57
• General sources
• Constraints on mHiggs
• Producing a Higgs LHC
• Higgsrsquo mechanism
• mSUGRA ndash ldquosuper gravityrdquo
• Other suggestions for SUSY breaking
• Producing exotics
• How do they then behave

mSUGRA ndash ldquosuper gravityrdquobull AKA cMSSMbull Gravity mediated SUSY

breakingndash Flavour-blind (no FCNCs)

bull Strong expt limitsndash Unification at high scales

bull Reduce SUSY parameter spacendash Common scalar mass M0

bull squarks sleptonsndash Common fermionic mass Mfrac12

bull Gauginosndash Common trilinear couplings A0

bull Susy equivalent of Yukawas

Programs includeeg ISASUSYSOFTSUSY

1016 GeV

EW scale

Iterate usingRenormalisationGroupEquations

Unification of couplings

Correct MZ MW hellip

Other suggestions for SUSY breaking

bull Gauge mediationndash Gauge (SM) fields in extra dimensions mediate SUSY breaking

bull Automatic diagonal couplings no EWSB

ndash No direct gravitino mass until Mpl

bull Lightest SUSY particle is gravitinobull Next-to-lightest can be long-lived (eg stau or neutralino)

bull Anomaly mediationndash Sequestered sector (via extra dimension)

bull Loop diagram in scalar part of graviton mediates SUSY breakingbull Dominates in absence of direct couplings

ndash Leads to SUSY breaking RGE β-functionsbull Neutral Wino LSPbull Charged Wino near-degenerate with LSP lifetime bull Interesting track signatures

Not exhaustive

Producing exotics

Time

standard

exotic

Time

standard

exotic

Time

standard

exotics

Time

standardexotics

bull If exotics can be produced singly they can decayndash No good for

Dark Matter candidate

bull If they can only be pair-produced they are stablendash Only

disappear on collision (rare)

Require an even number of exotic legs tofrom blobs(Conserved multiplicative quantum number)

If we want a good dark matter candidate

Require an even number of exotic legs tofrom blobs(Conserved multiplicative quantum number)

If we want a good dark matter candidate

No RP

With RP

How do they then behave

bull Events build from blobs with 2 ldquoexotic legsrdquo

bull A pair of cascade decays results

bull Complicated end result

bull Events build from blobs with 2 ldquoexotic legsrdquo

bull A pair of cascade decays results

bull Complicated end result

Time

standard

2 exotics

Production part

Time

standard

heavyexotic lighter

exotic

Decay part Time

Complete ldquoeventrdquo

= exotic= standard

• LHC Physics
• This morningrsquos stuffhellip
• Physics at TeV-scale
• Higgs mechanism - history
• Higgs mechanism why needed
• Pictorial representation
• Higgs field ldquoeats Goldstone bosonrdquo
• Constraints on the Higgs mass
• Perturbative limit
• Indirect Higgs bounds LEP Electroweak data
• Direct bounds Higgs searches LEP
• Higgs-Hunter Situation Report
• Slide 13
• The Large Hadron Collider
• General Purpose Detectors
• Definitions
• Making particles in hadron colliders
• LHCb
• LHCb Physics
• Slide 20
• ALICE
• Slide 22
• Couplings of the SM Higgs
• Producing a Higgs
• Production cross-sections
• Decay of the SM Higgs
• Slide 27
• Example 1 H ZZ
• H ZZ
• H ZZ e+e- e+e-
• Example (2) H γγ
• Slide 32
• H γγ
• H γγ hellip backgrounds
• Significance
• After discovery of Higgs
• If no Higgs found
• Slide 39
• What is supersymmetry
• (S)Particles
• Why Supersymmetry
• Further advantages
• R-parity
• How is SUSY broken
• Sparticle Interactions
• Slide 47
• General features
• The ldquoreal thingrdquo (a simulation ofhellip)
• Standard Model backgrounds measure from LHC DATA
• Constraining SUSY masses
• Mass determination
• Other things to do with SUSY
• Standard Model Physics
• Other things to look forhellip
• Extra dimensions models
• Slide 57
• General sources
• Constraints on mHiggs
• Producing a Higgs LHC
• Higgsrsquo mechanism
• mSUGRA ndash ldquosuper gravityrdquo
• Other suggestions for SUSY breaking
• Producing exotics
• How do they then behave

Other suggestions for SUSY breaking

bull Gauge mediationndash Gauge (SM) fields in extra dimensions mediate SUSY breaking

bull Automatic diagonal couplings no EWSB

ndash No direct gravitino mass until Mpl

bull Lightest SUSY particle is gravitinobull Next-to-lightest can be long-lived (eg stau or neutralino)

bull Anomaly mediationndash Sequestered sector (via extra dimension)

bull Loop diagram in scalar part of graviton mediates SUSY breakingbull Dominates in absence of direct couplings

ndash Leads to SUSY breaking RGE β-functionsbull Neutral Wino LSPbull Charged Wino near-degenerate with LSP lifetime bull Interesting track signatures

Not exhaustive

Producing exotics

Time

standard

exotic

Time

standard

exotic

Time

standard

exotics

Time

standardexotics

bull If exotics can be produced singly they can decayndash No good for

Dark Matter candidate

bull If they can only be pair-produced they are stablendash Only

disappear on collision (rare)

Require an even number of exotic legs tofrom blobs(Conserved multiplicative quantum number)

If we want a good dark matter candidate

Require an even number of exotic legs tofrom blobs(Conserved multiplicative quantum number)

If we want a good dark matter candidate

No RP

With RP

How do they then behave

bull Events build from blobs with 2 ldquoexotic legsrdquo

bull A pair of cascade decays results

bull Complicated end result

bull Events build from blobs with 2 ldquoexotic legsrdquo

bull A pair of cascade decays results

bull Complicated end result

Time

standard

2 exotics

Production part

Time

standard

heavyexotic lighter

exotic

Decay part Time

Complete ldquoeventrdquo

= exotic= standard

• LHC Physics
• This morningrsquos stuffhellip
• Physics at TeV-scale
• Higgs mechanism - history
• Higgs mechanism why needed
• Pictorial representation
• Higgs field ldquoeats Goldstone bosonrdquo
• Constraints on the Higgs mass
• Perturbative limit
• Indirect Higgs bounds LEP Electroweak data
• Direct bounds Higgs searches LEP
• Higgs-Hunter Situation Report
• Slide 13
• The Large Hadron Collider
• General Purpose Detectors
• Definitions
• Making particles in hadron colliders
• LHCb
• LHCb Physics
• Slide 20
• ALICE
• Slide 22
• Couplings of the SM Higgs
• Producing a Higgs
• Production cross-sections
• Decay of the SM Higgs
• Slide 27
• Example 1 H ZZ
• H ZZ
• H ZZ e+e- e+e-
• Example (2) H γγ
• Slide 32
• H γγ
• H γγ hellip backgrounds
• Significance
• After discovery of Higgs
• If no Higgs found
• Slide 39
• What is supersymmetry
• (S)Particles
• Why Supersymmetry
• Further advantages
• R-parity
• How is SUSY broken
• Sparticle Interactions
• Slide 47
• General features
• The ldquoreal thingrdquo (a simulation ofhellip)
• Standard Model backgrounds measure from LHC DATA
• Constraining SUSY masses
• Mass determination
• Other things to do with SUSY
• Standard Model Physics
• Other things to look forhellip
• Extra dimensions models
• Slide 57
• General sources
• Constraints on mHiggs
• Producing a Higgs LHC
• Higgsrsquo mechanism
• mSUGRA ndash ldquosuper gravityrdquo
• Other suggestions for SUSY breaking
• Producing exotics
• How do they then behave

Producing exotics

Time

standard

exotic

Time

standard

exotic

Time

standard

exotics

Time

standardexotics

bull If exotics can be produced singly they can decayndash No good for

Dark Matter candidate

bull If they can only be pair-produced they are stablendash Only

disappear on collision (rare)

Require an even number of exotic legs tofrom blobs(Conserved multiplicative quantum number)

If we want a good dark matter candidate

Require an even number of exotic legs tofrom blobs(Conserved multiplicative quantum number)

If we want a good dark matter candidate

No RP

With RP

How do they then behave

bull Events build from blobs with 2 ldquoexotic legsrdquo

bull A pair of cascade decays results

bull Complicated end result

bull Events build from blobs with 2 ldquoexotic legsrdquo

bull A pair of cascade decays results

bull Complicated end result

Time

standard

2 exotics

Production part

Time

standard

heavyexotic lighter

exotic

Decay part Time

Complete ldquoeventrdquo

= exotic= standard

• LHC Physics
• This morningrsquos stuffhellip
• Physics at TeV-scale
• Higgs mechanism - history
• Higgs mechanism why needed
• Pictorial representation
• Higgs field ldquoeats Goldstone bosonrdquo
• Constraints on the Higgs mass
• Perturbative limit
• Indirect Higgs bounds LEP Electroweak data
• Direct bounds Higgs searches LEP
• Higgs-Hunter Situation Report
• Slide 13
• The Large Hadron Collider
• General Purpose Detectors
• Definitions
• Making particles in hadron colliders
• LHCb
• LHCb Physics
• Slide 20
• ALICE
• Slide 22
• Couplings of the SM Higgs
• Producing a Higgs
• Production cross-sections
• Decay of the SM Higgs
• Slide 27
• Example 1 H ZZ
• H ZZ
• H ZZ e+e- e+e-
• Example (2) H γγ
• Slide 32
• H γγ
• H γγ hellip backgrounds
• Significance
• After discovery of Higgs
• If no Higgs found
• Slide 39
• What is supersymmetry
• (S)Particles
• Why Supersymmetry
• Further advantages
• R-parity
• How is SUSY broken
• Sparticle Interactions
• Slide 47
• General features
• The ldquoreal thingrdquo (a simulation ofhellip)
• Standard Model backgrounds measure from LHC DATA
• Constraining SUSY masses
• Mass determination
• Other things to do with SUSY
• Standard Model Physics
• Other things to look forhellip
• Extra dimensions models
• Slide 57
• General sources
• Constraints on mHiggs
• Producing a Higgs LHC
• Higgsrsquo mechanism
• mSUGRA ndash ldquosuper gravityrdquo
• Other suggestions for SUSY breaking
• Producing exotics
• How do they then behave

How do they then behave

bull Events build from blobs with 2 ldquoexotic legsrdquo

bull A pair of cascade decays results

bull Complicated end result

bull Events build from blobs with 2 ldquoexotic legsrdquo

bull A pair of cascade decays results

bull Complicated end result

Time

standard

2 exotics

Production part

Time

standard

heavyexotic lighter

exotic

Decay part Time

Complete ldquoeventrdquo

= exotic= standard

• LHC Physics
• This morningrsquos stuffhellip
• Physics at TeV-scale
• Higgs mechanism - history
• Higgs mechanism why needed
• Pictorial representation
• Higgs field ldquoeats Goldstone bosonrdquo
• Constraints on the Higgs mass
• Perturbative limit
• Indirect Higgs bounds LEP Electroweak data
• Direct bounds Higgs searches LEP
• Higgs-Hunter Situation Report
• Slide 13
• The Large Hadron Collider
• General Purpose Detectors
• Definitions
• Making particles in hadron colliders
• LHCb
• LHCb Physics
• Slide 20
• ALICE
• Slide 22
• Couplings of the SM Higgs
• Producing a Higgs
• Production cross-sections
• Decay of the SM Higgs
• Slide 27
• Example 1 H ZZ
• H ZZ
• H ZZ e+e- e+e-
• Example (2) H γγ
• Slide 32
• H γγ
• H γγ hellip backgrounds
• Significance
• After discovery of Higgs
• If no Higgs found
• Slide 39
• What is supersymmetry
• (S)Particles
• Why Supersymmetry
• Further advantages
• R-parity
• How is SUSY broken
• Sparticle Interactions
• Slide 47
• General features
• The ldquoreal thingrdquo (a simulation ofhellip)
• Standard Model backgrounds measure from LHC DATA
• Constraining SUSY masses
• Mass determination
• Other things to do with SUSY
• Standard Model Physics
• Other things to look forhellip
• Extra dimensions models
• Slide 57
• General sources
• Constraints on mHiggs
• Producing a Higgs LHC
• Higgsrsquo mechanism
• mSUGRA ndash ldquosuper gravityrdquo
• Other suggestions for SUSY breaking
• Producing exotics
• How do they then behave