17 april. 2005,aps meeting, tampa,floridas. bhattacharya 1 satyaki bhattacharya beyond standard...

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 1

Satyaki

Bhattacharya

Beyond Standard Beyond Standard Model Higgs Model Higgs

Search at LHCSearch at LHC

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 2

* numbers are for barrel

data taking starts 2007

Startup Luminosity 1033 cm-2/s

that is: 10 fb-1 per year

Silicon Tracker15 ( )%T

TT

p p TeVp

2.7% 0.150.5% E

E EE

PbWO4 ECAL

sampling brass HCAL 120

5%E

E E

solenoid4Tesla field

1.0 1.5%@100T

T

pglobal GeV

p

MUON Chambers

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 3

Higgs in Higgs in MSSM MSSM

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 4

MSSM Higgs sector MSSM Higgs sector

01

1

H

H

02

2

H

H

Two Higgs doublets

8 real Higgs fields( 4 complex fields)

3 fields are

gauged away

01

0

0 02

cos sin

sin cos

H

h

0 01 2

0 , ,, , A H H

All masses, and mixing angle are determined by two independent parameters, generally taken as

tan – ratio of vacuum expectation values of the two doubletsMA – mass of pseudoscalar Higgs A

pseudoscalar Higgs

charged Higgs

heavy Higgs

light Higgs

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 5

MSSM Higgs Production MSSM Higgs Production

h production x-sections similar to SM higgs in decoupling regionggh largest

ggH/A most important at low tan

at high tangg/qqHbb dominant for H/A

for H± tttH-bis most important

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 6

CMS Detector: schematic X-sectional view

HCAL

ECAL

TRACKER

h h Two clean electromagnetic clusters(For unconverted photons)

Backgrounds: gg,qq,qgq @low luminosityjet-jet 105 events/sjet+photon 102 events/s2 photon 1 event/12.5sHiggs 1 event/25sh2photon 1 event/10,000s

@low luminosityjet-jet 105 events/sjet+photon 102 events/s2 photon 1 event/12.5sHiggs 1 event/25sh2photon 1 event/10,000s

two photon background

gamma+jet background

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 7

hh mass resolutionmass resolution

=646MeVe

ven

ts/5

0M

eV

mfor 130 GeV Higgs

CMS full detector simulation. Ref: CMS Note 2003/033

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 8

A/HA/H jets + X jets + X

backgrounds: Z/2multijets faking tt and W+jet with W

reduce background by requiring: high pt narrow jet, isolation, b-tag, impact parameter

NLO x-section used

Signal:Production: ggbbH/A and ggH/ADecay: H/A+

MA 500GeV: .Br=0.188pbMA 200GeV: .Br=9.53pb

~15% mass resolution

Higgs signal over total backgroundPythia simulation

Ref: CMS Note 2003/006

Mass can be reonstructed assuming ||

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 9

h discovery @ 30fbh discovery @ 30fb-1-1

Decay branching ratios and searches for h are like SM Higgs

Ref: CMS Note 2003/033

5 discovery with 30 fb-1 possible in this region using h decay

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 10

A/H and HA/H and H± ± Discovery RegionsDiscovery Regions

At large tanAt large tan A/H coupling to A/H coupling to down type fermion is strong and down type fermion is strong and H production with bH production with bb b and H and H decay to decay to become important become important

For charged Higgs associated For charged Higgs associated production with top is dominantproduction with top is dominant

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 11

SummarySummary

• At LHC Higgs mass range between LEP bounds and ~1 TeV can be probed

• Atleast one MSSM Higgs will be found in entire MA-tan plane

• All MSSM Higgs should be visible in large region of the parameter space

• 5 discovery possible with 30 fb-1 in large region of the parameter space

• Few hundred MeV mass resolution for light Higgs from h

cmsdoc.cern.ch/~anikiten/cms-higgs/Higgs Working Group Summary, Les Houches 2004,hep-ph0406152

for more information

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 12

The EndThe End

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 13

Higgs Production in MSSM(details)Higgs Production in MSSM(details)

• H/A production– ggH/A, gg/qqbbH/A– g(AVV)=0 no VBF– At large tanβ

• VBF suppressed for H• g(A/Hbb) enhanced

~90% bbH/A for tanβ>10 and MA>300 GeV

– H SM-like near lower mass limit ( high tanβ, small

MA)VBF significant

• h production– h SM-like for MA>mh

max

• H± productionFor MH±<Mt : tttH±b

For MH±>Mt:

– ggtbH±,H+H-,W±H±

– gbtH±

– qqH±

Higgs couplings with up(u) down(d) fermions and vector bosons (v)

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 14

MSSM Higgs Production (updated from M. Spira)MSSM Higgs Production (updated from M. Spira)

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 15

MSSM Higgs Production (ii)MSSM Higgs Production (ii)

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 16

channels considered for a SUSY Higgschannels considered for a SUSY Higgs• H/h , bb

– H->bb in WH,ttH– h-> in Wh, tth->l

• H/hZZ*/ZZ4l • h/H/A(e/jETeET, jjET

– Including qqH,ttH,WH

• H+from tt• H+, H+tb for MH+

>Mt

• AZh with hbb• A• H/A ij• H±+

~ ~ ~ ~ ~

~

~

~

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 17

A/HA/H jets + X (detailed efficiency) jets + X (detailed efficiency)

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 18

H/A H/A

• ppbbH/A + X with H/A

2soft(ET< 50GeV) b jets

– Use b-tag against Z/* background

– Use central jet veto against tt

Mass resolution 1%, |mH-mA| ~ 2 GeVH/A peaks superimposed

(mass difference can be upto ~ 5.5 GeV)

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 19

CMS Trigger RatesCMS Trigger Rates

CMS total level1 rate is 16 kHz at startupTotal High Level Trigger (HLT) is 100 Hz.

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 20

Extra Slides on Extra Slides on Standard Model Standard Model

HiggsHiggs

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 21

Higgs production at LHCHiggs production at LHCggH

High gluon flux – dominant although loop process

Vector Boson Fusion (VBF)

10% at MH=100GeV

Comparable to gg->H at MH=1 TeV

ttH, bbH,HW,HZ

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 22

Decays and Search StrategyDecays and Search StrategyMH < ~140 GeV

Hbb dominantggHbb : background too large

ttHttbb possible

H–small BR but very clean

MH < ~500 GeV 120-200 GeV

HWW*/WWll(serious t,Wtb background)

200-500 GeVHZZ4l gives highest sensitivity

between 200-500 GeV

MH > ~500 GeVH large, use channels with large BR,

HZZ/WW

VBF x-sec large and can be used

sear

chch

anne

ls

17 April. 2005,APS meeting, Tampa,Florida S. Bhattacharya 23

Discovery reach of CMSDiscovery reach of CMS

• CMS can probe the entire “allowed” mass range

• 5 discovery possible in few months in many channels

Total

HHZZl+l-l+l-HWWll