yu nakahama (cern) kek-ph 2013, march 4-7, 2013atlas.kek.jp/sub/ohp/2013/20130307_nakahama.pdf ·...

Yu Nakahama (CERN) KEK-PH 2013, March 4-7, 2013　

Contents !•  LHC and ATLAS successful operation at 8 TeV in 2012!

•  Recent Physics Results!–  Higgs!–  New Physics Searches, SUSY!

•  Summary!

ATLAS results, Yu Nakahama (CERN)! 2!

Large Hadron Collider!•  LHC is an energy-frontier collider at CERN in Suisse/France.!•  It provided the pp collisions at √s= 8 TeV to ATLAS detector.!

p-‐

p-‐


ATLAS detector!•  ATLAS detector is a multi-purpose detector that can directly

explore energy scale from O(10) GeV to O(1) TeV. !•  We finished three-year successful operation during the Run-1

on 17/12/2012 for pp collisions (finally on 14/02/2013 for pPb).!

•  This talk will focus on the ATLAS recent results with the full dataset of the Run-1. No new data will come in two years. !

p-‐ p-‐


Month in YearJan Apr Jul Oct

]-1De

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35 = 7 TeVs2010 pp = 7 TeVs2011 pp = 8 TeVs2012 pp

ATLAS Online Luminosity 2012: 21 fb-1 at 8 TeV!

2011: 6 fb-1 at 7 TeV!

2010: 0.05 fb-1 at 7 TeV!

Data samples in 2012!•  Total integrated luminosity for analyses: 21 fb-1 at √s = 8 TeV.! 5 fb-1 at √s = 7 TeV. !

•  Doubled peak luminosity up to L = 7.7×1033 s−1cm−2.!–  At L = 7×1033 s−1cm−2 at 8 TeV

pp collisions, 560 Higgs bosons of mass 125 GeV (σppH = 22.3 pb) are produced in ATLAS and CMS per hour.!

–  In other words, every 45 minutes, 1 H γγ was produced and every 3 days one H ZZ(*) 4 leptons (lepton=e/µ). !


ATLAS Triggering system!•  An example of one of the main sub-systems in data-taking.!•  From pp collisions at 20 MHz, only physics signatures in

interest were selected online by the triggering system and recorded at 600 Hz to the computing storage.!–  Based on ~ 400 patterns of physics

signatures for 2012 data-taking.!–  For example,

a single electron with pT> 24 GeV, a combination of a jet with pT> 80 GeV and a missing transverse energy ET

miss> 100 GeV. !

Trigger Rate!

20 MHz!

75 kHz!

5 kHz!

600 Hz(average)!

Three-level Trigger System!Hardware trigger!

Software trigger on computing nodes!

Event filter!


Major experimental challenge in 2012!

Month in 2010 Month in 2011 Month in 2012Jan Apr Jul Oct Jan Apr Jul Oct Jan Apr Jul Oct

Peak

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= 7 TeVs = 7 TeVs = 8 TeVsATLASOnline Luminosity

Month in 2010 Month in 2011 Month in 2012Jan Apr Jul Oct Jan Apr Jul Oct Jan Apr Jul Oct

Peak

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= 7 TeVs = 7 TeVs = 8 TeVsATLASOnline Luminosity

2011 2012

LHC design

Peak interactions per crossing


•  Doubled increase of luminosity and pileup, interactions per bunch-crossing, would induce linear increase of trigger output rate or more.!

•  In average, ~20 interactions per bunch-crossing observed.!–  Up to 40 interactions at peak luminosity,

exceeding the LHC design (~25). !

–  Sizable impact on reconstruction of jets, ET

miss and tau as well as on triggerin data-taking.!

•  Online pileup-suppression by all three-level triggers was newly implemented. We have succeeded to achieve almost no impact for physics event selection in 2012. !

ATLAS publications!

On Mar 05: !•  ATLAS produced

239 papers using collision data!

•  454 preliminary conference notes!

Small extraction of huge amount of results available.!

http://atlasresults.web.cern.ch/atlasresults!

8!

Available huge statistics allows to perform powerful total and differential cross-section measurements even in rare channels such as dibosons.!

9!

ATLAS SM cross section measurements!•  Cross-section measurements from inclusive W and Z to ZZ

production were performed for:!–  precise test of the SM theory MC generators and PDFs are found

to describe the ATLAS data very well. !–  probing of New Physics such as anomalous triple gauge boson

coupling in all diboson channels agreed with the SM. Resulting limits approaching precision of combined LEP experiments or exceeding it.!

–  understanding of background structure for Higgs and New Physics searches.!

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-113 fb

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-11.0 fb

-135 pb

-135 pb

tt t WZ ZZ

= 7 TeVsLHC pp Theory

)-1Data (L = 0.035 - 4.6 fb

= 8 TeVsLHC pp Theory

)-1Data (L = 5.8 - 20 fb

ATLAS PreliminaryATLAS PreliminaryATLAS Preliminary


New!

A new era, new challenges!Higgs physics moved from searches to property measurements. !Huge efforts spent on examining of systematic effects and designing of robust analyses.!

11!

Discovery of a new boson!•  ATLAS and CMS discovered a new boson with mass of ~125

GeV by combination of Hγγ, ZZ(*)(4l), and WW(lνlν) channels using the data by June 2012.!–  Clear peak of mγγ distribution in Hγγ could be seen.!–  p-value for discovery was 5.9 σ.!

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Phys. Lett. B 716 (2012) 1-29!

5.9 σ at ~125 GeV!

After the Higgs discovery!•  ATLAS keeps efforts after a new boson discovery.!

− Property measurements (mass, spin/CP, and coupling) of the new boson with Hdiboson channels, Hγγ, ZZ(*)(4l), and WW(lνlν).!

− Searches for Hfermion pairs channels, Hττ and Hbb.!− Searches for HZγ, Hµ+µ- rare channels!− Searches for BSM Higgs with H ZZ(*)(4l) in high mass region and

ZH, Hinvisible in low mass region. !

•  All results shown today are the recent ones: !–  for Moriond EW 2013 yesterdayʼs evening or !–  for HCP 2012 in November.!


•  (Four production) x (five decay channels) are possible.!–  12 modes out of 20 are experimentally measurable in ATLAS.!

•  Calculations of cross sections and branching fractions for analysis use were made by common efforts by ATLAS, CMS, and theorists (Yellow Report CERN-2012-002).!

SM Higgs productions and decay channels!

Higgs with MH~125 GeV!


Gluon Fusion (ggF): 19.5 pb (87%)

Vector Boson Fusion (VBF): 1.6 pb (7%)

Associated production with W/Z (VH): 1.1 pb (5%)

Associated production with ttbar (ttH): 0.1 pb (1%)

Hγγ

HWWlνlν

HZZ(*)4l

Hττ

Hbb

Production

Decay channel

Hγγ: Analysis strategy •  Re-optimized analysis 7 TeV (5 fb-1) and 8 TeV (21 fb-1).!

–  For coupling measurements. !•  Golden mode in low mass!

–  Low BR (~ 0.2%), but clear γγ signatures with narrow mass peak.!

•  Reconstruct 2 energetic isolated photons!–  photon pT > 40, 30 GeV!–  mγγ

2= 2 Eγ1 Eγ2 (1-cosθ)!•  Major background is

irreducible ppγγ continuum. !–  ~75% of the total background!–  Estimated by sideband data.!

142681 events are found in 100<mγγ <160 GeV.!


ATLAS-CONF-2013-012!

New!

Hγγ: Selection categories !•  Analysis is optimized to measure couplings for each

production processes. !

New!

New!

–  14 exclusive categories are built in total. !–  Signal is extracted for each category by the fit

to mγγ distribution to include the different signal composition ratio and mass resolution.!

•  For example, 75 % purity in VBF tight category !

New!

New!



New!

Hγγ: Mass and signal strength!

•  The observed significance is 7.4 σ.!–  The expected one is 4.1 σ.!–  The signal is fully confirmed only

by a single channel.!

7.4 σ


•  Fitted mass value of the boson is 126.8 ± 0.2 (stat) ± 0.7 (syst) GeV.!

•  Best fit of signal strength μ=σ/σSM is μ=1.65 ± 0.24 (stat) ± 0.25 (syst).!–  2.3 σ deviation from the SM!

Best fit values of signal strength μ=σ/σSM vs mH!Local p0 values vs mH!


New!

Hγγ: couplings and production processes !•  Signal strength for each production mode can be disentangled to understand the

deviation of the signal strength.!

μ(ggF+ttH) vs. μ(VBF+VH)!

Production processes associated with either top (ggF+ttH) or gauge (VBF+VH) couplings:!

Further split into VBF and VH!

Uncertainties improved by ~30% (27%) for VBF (VH) production signal strengths from last public results. !

Agreed with SM expectations at 2σ level.!



New!

H→ZZ(*)→4l: Analysis strategy!•  Re-optimized analysis 7 TeV (4.8 fb-1) and 8 TeV (20.7 fb-1).!

–  To measure coupling with VBF and VH categories for the first time. !•  Golden mode in wide mass range!

–  Mass peak fully reconstructible, high resolution, low background !–  But, due to small BR, signal statistics is small.!–  Good for mass, spin, CP measurements.!

•  Reconstruct 2 pairs of same-flavor, opposite-charge leptons !

•  lepton pT > 20, 15,10, 7 (6) GeV (µ)!•  4μ is the dominant channel.!

•  Major background is irreducible ZZ(*) continuum, estimated by MC.!

32 events are found in 120 <m4l<130 GeV, where 15.9±2.1 from SM Higgs.!



New!

0+ !0-

H→ZZ(*)→4l: Spin and CP!•  Fully reconstructed final state allows to measure Spin and CP!

–  5 angles (production, decay) and 2 Z mass (m12, m34)

•  0+ (SM) hypothesis is discriminated against JCPassuming purely ggF production.!

0+ is favored fully over 0- and 1+ at 97.8% CL, and slightly over 1+, 2- (pseudo-tensor) and 2+

m (graviton-like tensor with minimal couplings) at ~ 80 % CL. !

Example: 0+ vs. 0- ! 0- is excluded with 99.6 %

CL in favored of 0+. !

20!


p0=0.0022!p0=0.40!

Matrix-element-based likelihood that distinguishes 0- vs 0+ !

New!

Also spin analysis of Hγγ on 0+ vs 2+ with 13 fb-1 at 8 TeV ![ATLAS-CONF-2012-168]!

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(0 jets)!e(*)WWH

HWW(*)eν+µν: Analysis strategy

0-jet with leading electron

mT distribution

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(1 jet)e!(*)WWH

1-jet with leading muon

•  Re-optimized analysis 7 TeV (4.8 fb-1) and 8 TeV (13 fb-1).!

•  Sensitive in high mass region!–  Highest BR in the range 130-600 GeV,

but one of the most challenging channels.!–  Mass peak is not reconstructible due to νν.!

•  Counting experiment based on mT. !

–  Exploit spin-0 Higgs hypothesis !•  By mll<50 GeV, ΔΦll<1.8.!

–  4 categories are built!•  Based on (0 or 1 jet) x leading (e or µ).!

–  Dominant backgrounds are WW and ttbar. !•  Fully estimated by control-region data.!



HWW(*)eν+µν: Results!•  Background subtracted mT

distribution with 125 GeV Higgs!

[Background subtracted! data and signal MC

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H [125 GeV]


(0/1 jets)e!/!e(*)WWH

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ATLAS Preliminary

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(0/1 jets)e"/"e(*)WWH

µ = 1.5 ± 0.6 at 125 GeV. !Observed significance is 2.6σ [expected: 1.9σ].!

Statistical errors for data and background subtraction shown!

•  Background-only p-value!



Hττ: Analysis strategy Re-optimized 7+ 8 TeV (13 fb-1) analysis !•  Three categories are lep-lep, lep-had and had-had.!

− VBF: 2-jets, mjj, Δηjj cuts!− Boosted: not VBF, high pT(ττ) (>100-70 GeV)!− Other categories: 0-jet, 1-jet, not VBF nor Boosted !

•  Discriminating variable is mττ, reconstructed with Missing Mass Calculator (MMC).!− exploiting correlations between ET

miss and visible decay products. !

− Resolution is 13% ~ 20%, best for boosted τ.!

•  Dominant backgrounds are Z ττ, also top and multi-jets for had-had.!

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Boostedhade + had!

lepton+hadron boosted

hadron+hadron, H+2jets VBF



Hττ: a VBF candidate event!

ETmiss

H ττ (doubly hadronic) candidate in a VBF channel (mMMC = 131 GeV)!


Hττ: Results!Combined and re-optimized 7+ 8 TeV analysis total of 25 exclusive fit categories!•  Available statistics allows meaningful VFB vs. non-VBF scan, similar sensitivity in

both processes, but best VBF constraint among all Higgs decays. !

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µ = 0.7 ± 0.7 at 125 GeV. !95% CL limit is 1.9 [ expected: 1.2 ] × SM.!Observed significance is 1.1 σ [expected: 1.7σ].!

VH production with Hbb!Combined and re-optimized 7+ 8 TeV (13 fb-1) analysis!•  Three categories requiring 2 b-jets are 0-lepton (νν), 1-lep (lν), 2-lep (ll).!

•  Further divided into 16 categories according to jet-multiplicity, bins of ET

miss, pT(W), pT(Z), in order to reduce background for boosted Higgs. !•  The discriminating variable is mbb with resolution of ~16%.!•  Main backgrounds are W/Z+b-jets and top.!

•  Check MC shapes and normalization in mbb and top control regions!

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> 200 GeVWT1 Lepton 2 Jets, p

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> 200 GeVmissT0 Lepton 2 Jets, E

Also new 7 TeV analysis of tt+H, with H bb [ATLAS-CONF-2012-135]!



VH production with Hbb: Results!Combined and re-optimized 7+ 8 TeV analysis 16 exclusive fit categories!•  Plot sums over categories, all non-diboson background subtracted.

Significance of peak with 4σ by VH. !•  Dominant systematics from the b-tagging and jet/ET

miss scales.!

[GeV]bbm50 100 150 200 250

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Observed (CLs)Expected (CLs)

1!

2!

PreliminaryATLAS-1 Ldt = 4.7 fb = 7 TeV, s

-1 Ldt = 13.0 fb = 8 TeV, s

), combinedbVH(b

VZ cross section ~5 times larger than VH!

Statistical errors for data and bkg subtraction shown!


µ = -0.4 ± 0.7(stat) ± 0.8(syst) at 125 GeV. !95 % CL limit is 1.8 [expected: 1.9] x SM.!


Updated Higgs mass!•  Combined mass obtained by Hγγ and ZZ(*):!

Agreed with 8 %. !



New!

€

mH =125.5 ± 0.2(stat)−0.6+0.5 (syst)GeV

Updated Higgs signal strength!•  Combined Signal strength by all channels:!‒  µ = σ/σSM =1.43 ± 0.21(± 0.16 (stat) ± 0.14 (sys)) at mH=125.5 GeV ! Compatibility with SM signal strength μ=1 is 11%. !

•  Combined cross-section ratio of VBF+VH over ggF+ttH by Hγγ, ZZ(*), ττ.!–  ! Agreed with SM expectation µ=1. !

€

µVBF+VH /µggF+ttH = 0.9-0.4+0.7



New!

Likelihood curves for the ratio μVBF+VH/μggF+ttH!

Other rare channels!•  SM HZγ

–  Discriminating variable is ∆m=mllγ-mll. !–  15 signal events expected with full 26 fb-1.

No excess observed.! 95% CL limit is 18.2 [ expected: 13.5 ] × SM.!

•  SM inclusive Hµ+µ- !–  Challenging due to small BF and huge background.! No excess observed with 8 TeV 21 fb-1.

95% CL limit is 9.8 [ expected: 8.2 ] × SM.!•  ZH, BSM Hinvisible!

–  No sensitivity with SM Higgs. But, searches for enhancements of the BSM invisible decay fraction over 115 <mH< 300 GeV.!

No excess observed.!ATLAS results, Yu Nakahama (CERN)! 30!

ATLAS-CONF-2013-009!New!



High Mass BSM Higgs Searches!•  HZZ(*)4l!

–  Search for an additional Higgs over 200 <mH<1000 GeV, assuming signal with SM-like line-shape, with full 26 fb-1.!

–  Upper Limit on cross-section x BR are set for each mH.!

•  Other sensitive channels in high mass region!–  No excess observed above SM in 200 <mH<600 GeV in HZZ(*)llνν,

llqq and HWWlνlν, lνqq with 7 TeV 5 fb-1. !ATLAS results, Yu Nakahama (CERN)! 31!


ggF VBF+VH

PLB 717 (2012) 29, PLB 717 (2012) 70, PLB 716 (2012) 62, and PLB 718 (2012) 391!

ATLAS responds with a broad and intense BSM research program. !

ATLAS thoroughly studies signatures for NP!•  Huge variety of models probed, but also model-independent results.


Mass scale [TeV]-110 1 10 210

Oth

erEx

cit.

ferm

.Ne

w qu

arks

LQV'

CIEx

tra d

imen

sions

jjmColor octet scalar : dijet resonance, µe

m, µ)=1) : SS eµe!L±± (DY prod., BR(HL

±±H llm), µµll)=1) : SS ee (!

L±± (DY prod., BR(HL

±±H (LRSM, no mixing) : 2-lep + jetsRW

Major. neutr. (LRSM, no mixing) : 2-lep + jets,WZT

mlll), "Techni-hadrons (LSTC) : WZ resonance (µµee/mTechni-hadrons (LSTC) : dilepton, #l

m resonance, #Excited lepton : l-jjmExcited quarks : dijet resonance,

jet#m-jet resonance, #Excited quarks :

llqmVector-like quark : NC, q"lmVector-like quark : CC, )

T2 (dilepton, M0A0 tt + A!Top partner : TT Zb

m Zb+X, !New quark b' : b'b' WtWt!)5/3T

5/3 generation : b'b'(Tth4

WbWb! generation : t't'th4jj"$jj, $$=1) : kin. vars. in %Scalar LQ pair (jj"µjj, µµ=1) : kin. vars. in !Scalar LQ pair (jj"=1) : kin. vars. in eejj, e!Scalar LQ pair (µT,e/mW* : tb

m tb, SSM) : ! (RW'tqm=1) :

R tq, g!W' (

µT,e/mW' (SSM) : $$mZ' (SSM) : µµee/mZ' (SSM) :

,missTEuutt CI : SS dilepton + jets + llm, µµqqll CI : ee &

)jj

m(&qqqq contact interaction : )jjm(

&Quantum black hole : dijet, F T

p'=3) : leptons + jets, DM /THMADD BH (ch. part.N=3) : SS dimuon, DM /THMADD BH (

tt,boostedm l+jets, !tt (BR=0.925) : tt !

KKRS g

"l",lTmRS1 : WW resonance, llll / lljjmRS1 : ZZ resonance,

/ ll##mRS1 : diphoton & dilepton, llm ED : dilepton, 2/Z1S

,missTEUED : diphoton + / ll##mLarge ED (ADD) : diphoton & dilepton,

,missTELarge ED (ADD) : monophoton + ,missTELarge ED (ADD) : monojet +

Scalar resonance mass1.86 TeV , 7 TeV [1210.1718]-1=4.8 fbL

massL±±H375 GeV , 7 TeV [1210.5070]-1=4.7 fbL

)µµ mass (limit at 398 GeV for L±±H409 GeV , 7 TeV [1210.5070]-1=4.7 fbL

(N) < 1.4 TeV)m mass (RW2.4 TeV , 7 TeV [1203.5420]-1=2.1 fbL

) = 2 TeV)R

(WmN mass (1.5 TeV , 7 TeV [1203.5420]-1=2.1 fbL

))T((m) = 1.1

T(am, Wm) + T)(m) =

T((m mass (

T(483 GeV , 7 TeV [1204.1648]-1=1.0 fbL

)W

) = MT)(m) - T*/T((m mass (T*/T

(850 GeV , 7 TeV [1209.2535]-1=4.9-5.0 fbL

= m(l*))+l* mass (2.2 TeV , 8 TeV [ATLAS-CONF-2012-146]-1=13.0 fbL

q* mass3.84 TeV , 8 TeV [ATLAS-CONF-2012-148]-1=13.0 fbL

q* mass2.46 TeV , 7 TeV [1112.3580]-1=2.1 fbL

)Q/m" = qQ,VLQ mass (charge 2/3, coupling 1.08 TeV , 7 TeV [ATLAS-CONF-2012-137]-1=4.6 fbL

)Q/m" = qQ,VLQ mass (charge -1/3, coupling 1.12 TeV , 7 TeV [ATLAS-CONF-2012-137]-1=4.6 fbL

) < 100 GeV)0

(AmT mass (483 GeV , 7 TeV [1209.4186]-1=4.7 fbL

b' mass400 GeV , 7 TeV [1204.1265]-1=2.0 fbL

) mass5/3

b' (T670 GeV , 7 TeV [ATLAS-CONF-2012-130]-1=4.7 fbL

t' mass656 GeV , 7 TeV [1210.5468]-1=4.7 fbL

gen. LQ massrd3538 GeV , 7 TeV [Preliminary]-1=4.7 fbL

gen. LQ massnd2685 GeV , 7 TeV [1203.3172]-1=1.0 fbL

gen. LQ massst1660 GeV , 7 TeV [1112.4828]-1=1.0 fbL

W* mass2.42 TeV , 7 TeV [1209.4446]-1=4.7 fbL

W' mass1.13 TeV , 7 TeV [1205.1016]-1=1.0 fbL

W' mass430 GeV , 7 TeV [1209.6593]-1=4.7 fbL

W' mass2.55 TeV , 7 TeV [1209.4446]-1=4.7 fbL

Z' mass1.4 TeV , 7 TeV [1210.6604]-1=4.7 fbL

Z' mass2.49 TeV , 8 TeV [ATLAS-CONF-2012-129]-1=5.9-6.1 fbL

+1.7 TeV , 7 TeV [1202.5520]-1=1.0 fbL

(constructive int.)+13.9 TeV , 7 TeV [1211.1150]-1=4.9-5.0 fbL

+7.8 TeV , 7 TeV [ATLAS-CONF-2012-038]-1=4.8 fbL

=6)- (DM4.11 TeV , 7 TeV [1210.1718]-1=4.7 fbL

=6)- (DM1.5 TeV , 7 TeV [1204.4646]-1=1.0 fbL

=6)- (DM1.25 TeV , 7 TeV [1111.0080]-1=1.3 fbL

massKK

g1.9 TeV , 7 TeV [ATLAS-CONF-2012-136]-1=4.7 fbL

= 0.1)PlM/kGraviton mass (1.23 TeV , 7 TeV [1208.2880]-1=4.7 fbL

= 0.1)PlM/kGraviton mass (845 GeV , 7 TeV [1203.0718]-1=1.0 fbL

= 0.1)PlM/kGraviton mass (2.23 TeV , 7 TeV [1210.8389]-1=4.7-5.0 fbL

-1 ~ RKKM4.71 TeV , 7 TeV [1209.2535]-1=4.9-5.0 fbL

-1Compact. scale R1.41 TeV , 7 TeV [ATLAS-CONF-2012-072]-1=4.8 fbL

=3, NLO)- (HLZ SM4.18 TeV , 7 TeV [1211.1150]-1=4.7 fbL

=2)- (DM1.93 TeV , 7 TeV [1209.4625]-1=4.6 fbL

=2)- (DM4.37 TeV , 7 TeV [1210.4491]-1=4.7 fbL

Only a selection of the available mass limits on new states or phenomena shown*

-1 = (1.0 - 13.0) fbLdt. = 7, 8 TeVs

ATLASPreliminary

ATLAS Exotics Searches* - 95% CL Lower Limits (Status: HCP 2012)Exotics Models:!Extra dimensions:! !RS KK Graviton ! ! (dibosons, dileptons, diphotons)! !RS KK gluons (top antitop)! !ADD (monojets, monophotons, ! dileptons, diphotons)! !KK Z/gamma boosns (dileptons)!Grand Unification symmetries !

!(dielectons, dimuons, ditaus)! !Leptophobic topcolor Z' boson ! ! (dilepton ttbar, l+j, all had)!S8- color octet scalars (dijets)!String resonance (dijets,)!Benchmark Sequential SM Z', W' !W' (lepton+MET, dijets, tb)!W* (lepton+MET, dijets)!Quantum Black Holes (dijet)!Black Holes (l+jets, same sign leptons)!Technihadrons (dileptons, dibosons)!Dark Matter! !WIMPs (Monojet, monophotons)!Excited fermions! !q*, Excited quarks (dijets, photon+jet)! !l*, excited leptons (dileptons+photon)!Leptoquarks (1st, 2nd, 3rd generations)!Higgs -> hidden sector ! (displaced vertices, lepton jets)!Contact Interaction! !llqq CI! !4q CI (dijets)!Doubly charged Higgs (! !multi leptons, same sign leptons)!4th generation! !t'->Wb, t'->ht, b'-Zb, b'->Wt! ! (dileptons, same sign leptons, l+J)!VLQ-Vector Like quarks !Magnetic Monopoles (and HIP)!Heavy Majorana neutrino and RH W!

Some results in the backup slides.!

Broad and deep SUSY research program in ATLAS!

Introduction to SUSY search status!•  25 papers at 7 TeV with full dataset in 2011!•  15 preliminary 8 TeV results! No discovery yet.!

•  Example from inclusive searches for squarks and gluinos in 0-lepton+(2-6) jet analysis with 8 TeV 5 fb-1.!


gluino mass [GeV]800 1000 1200 1400 1600 1800 2000 2200 2400

squa

rk m

ass

[GeV

]

800

1000

1200

1400

1600

1800

2000

2200

2400

2600

2800) = 0 GeV0

1Squark-gluino-neutralino model, m(

=8 TeVs, -1 L dt = 5.8 fb

0-lepton combined

ATLAS

)theorySUSY1 !Observed limit (

)exp1 !Expected limit (

, 7 TeV)-1Observed limit (4.7 fb

Preliminary


m( q) ≈ m( g) < 1.5 TeVm( q) < 1.4 TeV (∀ m( g) < 2 TeV)m( g) < 1 TeV (∀ m( q) < 2 TeV)

Limits from this model:!

“Natural” SUSY!•  Lightest squarks are stop/sbottom. Gluinos possibly too

heavy, gauginos might be accessible.!•  Stop and sbottom have lower cross-sections and larger SM

backgrounds require dedicated searches. Strong and strategic approach is performed by ATLAS.!


P1

P2

b̃/t

b̃/t*

b/t

!̃ 01

!̃ 01

b̄/t

˜

˜

¯

Direct b/t pair production!~!~!

P1

P2g̃

g̃

b̄/t

b/t

!̃ 01

!̃ 01

b̄/t

b/t

¯

¯

Gluino-mediated b/t production!~!~!

also: t → b + χ1+

[GeV]1t

~m200 250 300 350 400 450 500 550 600 650

10

+mt <

m1t~m

150 200 250 300 350 400 450 50

)1

0 m! = 2

1"

( m1

"

+mb

< m1t~m

( = 106 GeV)1" > m

10 m

< 106 GeV 1" m

( = 150 GeV)1" > m

10 m

-10)

1t~ =

m1"

( m1"

> m

10

m

[GeV

]10

m

0

50

100

150

200

250

300

350 =8 TeVs -1 = 13 fbintL

1

0 m! = 2 "

1m

-1 = 13 fbintL - 10 GeV

1t~ = m"

1m

-1 = 13 fbintL

= 150 GeV"

1m

-1 = 13 fbintL = 106 GeV"

1m

-1 = 4.7 fbintL

-1 = 4.7 fbintL -1 = 13 fbintL

ATLAS preliminary

Status: December 2012

=7 TeVs -1 = 4.7 fbintL1L ATLAS-CONF-2012-166-1L ATLAS-CONF-2012-1662L ATLAS-CONF-2012-1671L ATLAS-CONF-2012-166

0L [1208.1447], 1L [1208.2590], 2L [1209.4186]2L [1208.4305], 1-2L [1209.2102]--1-2L [1209.2102]

production1t~1t

~

10+(*) W

1",

1" b+ 1t

~10 t 1t

~

10 t 1t

~ = 106 GeV"

1, m

1" b+ 1t

~

= 150 GeV"1

, m1" b+ 1t

~

- 10 GeV1t

~ = m"1

, m1" b+ 1t

~

10 m! = 2 "

1, m

1" b+ 1t

~

Observed limits)theoObserved limits (-1

Expected limits

Direct stop production!•  Assuming stop decaying top + neutralino and b + chargino.

•  Direct stop production features similar final states as top pairs, searches use 0/1/2-lepton+b-jets+ET

miss final states and depend on sparticle masses and stop decays.!–  Excluded stop-neutralino mass region with up to 8 TeV 13 fb-1 data.!


ATLAS-CONF-2012-166, ATLAS-CONF-2012-167!

5 papers on 7 TeV:!1208.4305, 1209.2102, 1209.4186, 1208.2590, 1208.1447!

There is still room at low mass and higher stop mass. !

Note that our models are simplified. !

Deeply mines SUSY signature and model space!•  Strong push on naturalness dedicated searches, but also long-lived

particles and RPV. A bunch of updates with the full dataset are to come soon.


EW

3rd

gen

squ

arks

squ

arks

& g

luin

os

RP

V

Oth

er

LLP

Mass scale [TeV]-110 1 10

RPV

Long

-live

dpa

rticle

sEW dire

ct3r

d ge

n. s

quar

ksdi

rect

pro

duct

ion

3rd

gen.

sq.

glui

no m

ed.

Inclu

sive

sear

ches

,missTE) : 'monojet' + !WIMP interaction (D5, Dirac

Scalar gluon : 2-jet resonance pair qqq : 3-jet resonance pair" g~

,missTE : 4 lep + e#µ,eµ#ee"

01!$, 0

1!$l"Ll

~, -Ll

~+Ll

~ ,missTE : 4 lep + e#µ,eµ#ee"

01!$, 0

1!$W"

+1!$, -

1!$

+1!$

,missTEBilinear RPV CMSSM : 1 lep + 7 j's + resonance%)+µe("%#

$+X, %#$"LFV : pp

resonanceµe+"%#$+X, %#

$"LFV : pp + heavy displaced vertexµ (RPV) : µ qq" 0

1!$

%$GMSB : stable (full detector)&', ' R-hadrons : low t~Stable (full detector)&', ' R-hadrons : low g~Stable

±

1!$ pair prod. (AMSB) : long-lived ±

1!$Direct

,missTE : 3 lep + 01!$

)*(Z01!$

)*( W" 02!$±

1!$

,missTE) : 3 lep + ##$l(Ll

~#$), l##$l(Ll

~#Ll

~ " 02!$±

1!$

,missTE : 2 lep + 01!$#l")#$(l#l~"+

1!$, -

1!$

+1!$

,missTE : 2 lep + 01!$l"l~, Ll

~Ll

~ ,missTEll) + b-jet + " (natural GMSB) : Z(t~t~ ,missTE : 0/1/2 lep (+ b-jets) + 0

1!$t"t~, t~t~

,missTE : 1 lep + b-jet + 01!$t"t~, t~t~

,missTE : 2 lep + ±

1!$b"t~ (medium), t~t~

,missTE : 1 lep + b-jet + ±

1!$b"t~ (medium), t~t~

,missTE : 1/2 lep (+ b-jet) + ±

1!$b"t~ (light), t~t~ ,missTE : 3 lep + j's + ±

1!$t"1b~, b~b~

,missTE : 0 lep + 2-b-jets + 01!$b"1b~, b~b~

,missTE) : 0 lep + 3 b-j's + t~ (virtual 01!$tt"g~

,missTE) : 0 lep + multi-j's + t~ (virtual 01!$tt"g~

,missTE) : 3 lep + j's + t~ (virtual 01!$tt"g~

,missTE) : 2 lep (SS) + j's + t~ (virtual 01!$tt"g~

,missTE) : 0 lep + 3 b-j's + b~ (virtual 01!$bb"g~

,missTEGravitino LSP : 'monojet' + ,missTEGGM (higgsino NLSP) : Z + jets + ,missT

E + b + &GGM (higgsino-bino NLSP) : ,missTE + lep + &GGM (wino NLSP) : ,missTE + &&GGM (bino NLSP) : ,missTE + 0-1 lep + j's + % NLSP) : 1-2 %$GMSB ( ,missTE NLSP) : 2 lep (OS) + j's + l~GMSB (

,missTE) : 1 lep + j's + ±!$qq"g~ (±

!$Gluino med. ,missTEPheno model : 0 lep + j's + ,missTEPheno model : 0 lep + j's + ,missTEMSUGRA/CMSSM : 1 lep + j's + ,missTEMSUGRA/CMSSM : 0 lep + j's +

M* scale < 80 GeV, limit of < 687 GeV for D8)!m(704 GeV , 8 TeV [ATLAS-CONF-2012-147]-1=10.5 fbL

sgluon mass (incl. limit from 1110.2693)100-287 GeV , 7 TeV [1210.4826]-1=4.6 fbL

massg~666 GeV , 7 TeV [1210.4813]-1=4.6 fbL

massl~ > 0)122( or 121(), %l~(m)=µl

~(m)=el

~(m) > 100 GeV, 0

1!$(m(430 GeV , 8 TeV [ATLAS-CONF-2012-153]-1=13.0 fbL

mass+1!$$

> 0)122( or 121() > 300 GeV, 0


massg~ = q~ < 1 mm)LSP%(c1.2 TeV , 7 TeV [ATLAS-CONF-2012-140]-1=4.7 fbL

mass%#$ =0.05)1(2)33!=0.10, ,

311!(1.10 TeV , 7 TeV [Preliminary]-1=4.6 fbL

mass%#$ =0.05)132!=0.10, ,

311!(1.61 TeV , 7 TeV [Preliminary]-1=4.6 fbL

massq~ decoupled)g~ < 1 m, %, 1 mm < c-510) < 1.5211,( < -510)(0.3700 GeV , 7 TeV [1210.7451]-1=4.4 fbL

mass%$ < 20)'(5 < tan300 GeV , 7 TeV [1211.1597]-1=4.7 fbL

masst~683 GeV , 7 TeV [1211.1597]-1=4.7 fbL

massg~985 GeV , 7 TeV [1211.1597]-1=4.7 fbL

mass±

1!$ ) < 10 ns)±

1!$(%(1 < 220 GeV , 7 TeV [1210.2852]-1=4.7 fbL

mass±

1!$ ) = 0, sleptons decoupled)0

1!$(m), 0

2!$(m) = ±

1!$(m(140-295 GeV , 8 TeV [ATLAS-CONF-2012-154]-1=13.0 fbL

mass±

1!$ ) as above)#

$,l~(m) = 0, 0

1!$(m), 0

2!$(m) = ±


mass±

1!$ )))0

1!$(m) + ±

1!$(m(2

1) = #$,l

~(m) < 10 GeV, 0

1!$(m(110-340 GeV , 7 TeV [1208.2884]-1=4.7 fbL

massl~ ) = 0)0

1!$(m(85-195 GeV , 7 TeV [1208.2884]-1=4.7 fbL

masst~ ) < 230 GeV)0

1!$(m(115 < 310 GeV , 7 TeV [1204.6736]-1=2.1 fbL

masst~ ) = 0)0

1!$(m(230-465 GeV , 7 TeV [1208.1447,1208.2590,1209.4186]-1=4.7 fbL

masst~ ) = 0)0


masst~ ) = 10 GeV)±

1!$(m)-t~(m) = 0 GeV, 0


masst~ ) = 150 GeV)±

1!$(m) = 0 GeV, 0


masst~ ) = 55 GeV)0

1!$(m(167 GeV , 7 TeV [1208.4305, 1209.2102]-1=4.7 fbL

massb~ ))0

1!$(m) = 2 ±


massb~ ) < 120 GeV)0


massg~ ) < 200 GeV)0

1!$(m(1.15 TeV , 8 TeV [ATLAS-CONF-2012-145]-1=12.8 fbL









scale1/2F eV)-4) > 10G~

(m(645 GeV , 8 TeV [ATLAS-CONF-2012-147]-1=10.5 fbL

massg~ ) > 200 GeV)H~

(m(690 GeV , 8 TeV [ATLAS-CONF-2012-152]-1=5.8 fbL

massg~ ) > 220 GeV)0

1!$(m(900 GeV , 7 TeV [1211.1167]-1=4.8 fbL

massg~619 GeV , 7 TeV [ATLAS-CONF-2012-144]-1=4.8 fbL

massg~ ) > 50 GeV)0

1!$(m(1.07 TeV , 7 TeV [1209.0753]-1=4.8 fbL

massg~ > 20)"(tan1.20 TeV , 7 TeV [1210.1314]-1=4.7 fbL

massg~ < 15)"(tan1.24 TeV , 7 TeV [1208.4688]-1=4.7 fbL

massg~ ))g~(m)+0!$(m(2

1) = ±!$(m) < 200 GeV, 0

1!$(m(900 GeV , 7 TeV [1208.4688]-1=4.7 fbL

massq~ )0

1!$) < 2 TeV, light g~(m(1.38 TeV , 8 TeV [ATLAS-CONF-2012-109]-1=5.8 fbL

massg~ )0

1!$) < 2 TeV, light q~(m(1.18 TeV , 8 TeV [ATLAS-CONF-2012-109]-1=5.8 fbL

massg~ = q~1.24 TeV , 8 TeV [ATLAS-CONF-2012-104]-1=5.8 fbL massg~ = q~1.50 TeV , 8 TeV [ATLAS-CONF-2012-109]-1=5.8 fbL

Only a selection of the available mass limits on new states or phenomena shown.* theoretical signal cross section uncertainty.#All limits quoted are observed minus 1

-1 = (2.1 - 13.0) fbLdt* = 7, 8 TeVs

ATLASPreliminary

7 TeV results

8 TeV results

ATLAS SUSY Searches* - 95% CL Lower Limits (Status: Dec 2012)

Summary!•  ATLAS performs all areas of the physics program with the

2011 and 2012 data samples at 7 and 8 TeV in the Run1.!–  The Standard Model: !

•  By huge statistics data, the SM was tested very precisely.!–  Higgs with mass of ~125.5 GeV: !

•  All measurements, signal strength and spin/CP, in the Hdiboson channels, are consistent with the SM Scalar prediction.!

•  Started to confirm the signal strength by Hfermion-pair channels.!•  Started to searches for other Higgs in high mass region and by the rare

decay channels. !–  New Physics Searches, SUSY and Exotics: !

•  Physics beyond the SM did not show up yet. !•  Switched to focus on 3rd generation squark searches based on Natural

SUSY!•  After the two-year shutdown, enhancements of TeV scale objects in the

data sample at 13 TeV might give us some surprises. !


Higgs decays and sensitive channels!•  Five sensitive decay channels are considered.!

[GeV]HM100 150 200 250

BR

[pb]

!

-410

-310

-210

-110

1

10

LHC

HIG

GS

XS W

G 2

012

= 8TeVs

"l = e, ,",e =

q = udscb

bb# lWH

bb-l+ lZH

b ttbttH

-+ VBF H

-+

qq# lWW -l+ lWW

qq-l+ lZZ -l+ lZZ

-l+l-l+ lZZ

Decay Characteristics Hγγ The most important for low mass

region. High background but high mass resolution

HZZ(*) ZZ4l (l=e,µ) has small BR but low background and high mass resolution

HWW WWlνlν relevant at low and intermediate mass

Hττ Low mass region. Good signal and background ratio by vector boson fusion production

Hbb Low mass region, by associated production


Even

ts /

0.1

0

2000

4000

6000

8000

10000

12000

14000

16000

3 jetse+ATLAS Preliminary -1 Ldt = 5.8 fb

= 8 TeVsData

tt W+Jets MultijetZ+Jets Single Top Dibosons

Likelihood0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Dat

a / E

xpec

tatio

n

1

1.5

Even

ts /

0.1

0

2000

4000

6000

8000

10000

12000

14000

16000

180003 jets+!

ATLAS Preliminary -1 Ldt = 5.8 fb = 8 TeVsData

tt W+Jets MultijetZ+Jets Single Top Dibosons

Likelihood0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Dat

a / E

xpec

tatio

n

0.8

1

1.2

1.4

Understanding of top-pair production at LHC!•  Precision measurement already - all the work is on

understanding of systematics from top signal modeling.!–  Large variety of 7 TeV measurements were already published: 0/1/2-lepton

(including taus) agreed with theoretical prediction.!–  Measurement of 8 TeV cross-section in 1-lepton channel (5.8 fb–1) using

likelihood template fit agreed with theoretical prediction?!

Inclusive ttbar cross section (using m(t) = 172.5 GeV):!

σ = 241!± 2 (stat)! ± 31 (syst) ± 9 (lumi) pb!

Syst. dominated by MC signal modeling (ISR/FSR, generator, parton shower, PDF)!

Agreed with theory: !238 pb (HATHOR, approx. NNLO)!+ 22 !

- 24 !

8 TeV: ATLAS-CONF-2012-149!


Understanding of top-pair production at LHC!•  Precision measurement already - all the work is on

understanding of systematics from top signal modeling.!–  Large variety of 7 TeV measurements were already published: 0/1/2-lepton

(including taus) agreed with theoretical prediction.!–  Measurement of 8 TeV cross-section in 1-lepton channel (5.8 fb–1) using

likelihood template fit agreed with theoretical prediction?!

Inclusive ttbar cross section (using m(t) = 172.5 GeV):!

σ = 241!± 2 (stat)! ± 31 (syst) ± 9 (lumi) pb!

Systematic dominated by MC signal modeling (ISR/FSR, generator, parton shower, PDF)!

Agreed with theory: !238 pb (HATHOR, approx. NNLO)!+ 22 !

- 24 ! [TeV]s

1 2 3 4 5 6 7 8

[pb]

tt!

1

10

210

ATLAS Preliminary

NLO QCD (pp)Approx. NNLO (pp)

)pNLO QCD (p

) pApprox. NNLO (p

CDF

D0

32 pb±Single Lepton (8 TeV) 241 12 pb ±Single-lepton (7 TeV) 179

pb-14+17Dilepton 173

81 pb±All-hadronic 167 pb-10

+11Combined 177

6.8 7 7.2120140160

180200220

Grand-picture!


8 TeV: ATLAS-CONF-2012-149!

Some of the selected results are shown.!

ATLAS mines its data for NP in events with jets!•  Gradually approaching the limits of phase space!



[GeV]jjReconstructed m1000 2000 3000 4000 5000

[ dat

a - f

it ] /

fit

0

2

4

-1 = 13.0 fbdt L

=8 TeV, s[ data - fit ] / fit

(1500) 8 YTHIAq* P(2500) 8 YTHIAq* P(3000) 8 YTHIAq* P(3750) 8 YTHIAq* P

ATLAS Preliminary

2000 3000 40001

10

210

310

410

510 DataBackground

[GeV]jjReconstructed m2000 3000 4000

Even

tsSi

gnifi

canc

e

-2

0

2

ATLAS Preliminary

-1 = 13.0 fbdt L

= 8 TeVs

Data / fit ratio, compared to four q* models!Observed and fitted dijet mass!

m(q*) > 3.84 TeV (95% CL)!

New resonances decaying to top pairs!


q

q(‘)

t

t

Z’ ?

Maybe the Z’ is leptophobic and has topcolour only ?

If the Zʼ is very heavy, the outgoing tops will be strongly boosted; hadronic tops will be merged.!

New resonances decaying to top pairs!•  Searching for tt fully-hadronic resonances in boosted regime!


1211.2202, ATLAS-CONF-2012-136!

Two methods identify merged hadronic top decays!•  HEP-Top-Tagger uses substructure of “fat jets”!•  Top-Template-Tagger uses calorimeter templates!

Leading Jet Mass [GeV]120 140 160 180 200 220 240

Even

ts /

20 G

eV

0

10

20

30

40

50

60

70

Data 2011

tt

Multijet

ATLAS

= 7 TeVs

-1 L dt = 4.7 fb!

Mass [GeV]tt500 1000 1500 2000 2500 3000

Even

ts /

100

GeV

0

50

100

150

200

250

300

350Data 2011

= 1.3 pb!Z' (1 TeV)

ttMultijet

ATLAS-1 L dt = 4.7 fb"

= 7 TeVs

HEPTopTagger

m(tt) after HEP-Top-Tagger identification!

Jet mass of leading jets in Top-Template-Tagger

signal region!

Leptophobic topcolor Zʼ excluded up to 1 TeV at 95% CL !Boosted technique also exploited for other searches.!

yu nakahama (cern) kek-ph 2013, march 4-7, 2013atlas.kek.jp/sub/ohp/2013/20130307_nakahama.pdf ·...

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