Guoming CHEN12015-5-4 The Capability of CMS Detector Chen Guoming IHEP, CAS 2008.10.24, Beijing.

Guoming CHEN Guoming CHEN 1123/4/1823/4/18

The Capability of CMS The Capability of CMS DetectorDetector

Chen GuomingChen Guoming

IHEP, CASIHEP, CAS

2008.10.24, Beijing2008.10.24, Beijing

23/4/1823/4/18 Guoming CHEN Guoming CHEN 22

CMS

B field: 4TB field: 4T


CMS CMS ηη coveragecoverage


Inner Tracker Inner Tracker –– All Si All Si

5.4 m

Outer Barrel –TOB-

Inner Barrel –TIB-

End cap –TEC-Pixel

2,4

m

Inner Disks –TID-

210 m2 of silicon sensors6,136 Thin detectors (1 sensor)9,096 Thick detectors (2 sensors)9,648,128 electronics channels


Vertex detector: Si pixelVertex detector: Si pixel

space space resolutionresolution::

10 10 μμmm


Si Strip TRACKERSi Strip TRACKER


Momentum resolutionMomentum resolution


Material budgetMaterial budget


ECAL ECAL –– PbWO Crystals PbWO Crystals


ECAL Test Beam ModuleECAL Test Beam Module


Electron and Gamma Energy Electron and Gamma Energy ResolutionResolution


CMS - HCAL CMS - HCAL

Back-flange18 Brackets3 Layers of absorber

Made of brass and scintillator. Radiation tolerant scintillator and HPD photo transducer works in 4T field.


Jet energy resolutionJet energy resolution


CMS Muon SystemCMS Muon SystemThree types of gaseous Three types of gaseous

detectorsdetectors• Drift Tubes in barrel Drift Tubes in barrel

regionregion• 4 stations 4 stations

interleaved with interleaved with iron return yokeiron return yoke

• Cathod Strip Chambers Cathod Strip Chambers in endcap regionsin endcap regions

• 4 stations 4 stations interleaved with interleaved with iron return yokeiron return yoke

• Up to |Up to || < 2.4| < 2.4• Resistive Plate Resistive Plate

Chambers in both barrel Chambers in both barrel and endcapsand endcaps

• precise bunch precise bunch crossing ID for crossing ID for TriggerTrigger

• Up to |Up to || < 2.1| < 2.1


Barrel MUCHBarrel MUCH

Guoming CHEN Guoming CHEN 171723/4/1823/4/18

EndcapEndcapMUCHMUCH


Muon momentum resolutionMuon momentum resolution


Particle ID


Trigger Trigger

table: table: 2x102x103333 cmcm-2-2ss-1-1

TriggerTrigger ThresholdThreshold(GeV )(GeV )

Rate (Hz)Rate (Hz) Cuml. rate Cuml. rate (Hz)(Hz)

Inclusive electronInclusive electron 2929 3333 3333

Di-electronDi-electron 1717 11 3434

Inclusive photonInclusive photon 8080 44 3838

Di-photonDi-photon 40, 2540, 25 55 4343

Inclusive muonInclusive muon 1919 2525 6868

Di-muonDi-muon 77 44 7272

Inclusive tau-jetInclusive tau-jet 8686 33 7575

Di-tau-jetDi-tau-jet 5959 11 7676

1-jet * E1-jet * ETTmissmiss 180 * 123180 * 123 55 8181

1-jet OR 3-jet OR 1-jet OR 3-jet OR 4-jet4-jet

657, 247, 113657, 247, 113 99 8989

Electron * jetElectron * jet 19 * 4519 * 45 22 9090

Inclusive b-jetInclusive b-jet 237237 55 9595

Calibration etcCalibration etc 1010 105105

TOTALTOTAL 105105


CMS installationCMS installation


Beampipe installation before Beampipe installation before ClosureClosure


Final ClosureFinal Closure


Cosmic ray testCosmic ray test


Collimator SprayCollimator Spray


Tracker Alignment with cosmic Tracker Alignment with cosmic raysrays CRUZET4

TIB

Transverse impact point – using cosmics to align tracker


SummarySummary

• CMS has no dead region from -5 to 5 CMS has no dead region from -5 to 5 of of ηη

• CMS emphasizes muon, gamma and CMS emphasizes muon, gamma and electron measurementelectron measurement

• CMS was produced, installed and CMS was produced, installed and tested. Every piece works well, it is tested. Every piece works well, it is ready for physicsready for physics


Higgs searchHiggs search

New !


Probability of Higgs massProbability of Higgs mass

Jens ErlerJens Erler


H→H→γγγγis the first channel at CMS is the first channel at CMS


Discovery potential of H-Discovery potential of H->>

SMSM

Significance for SM Higgs MSignificance for SM Higgs MHH=130 GeV for 30 fb=130 GeV for 30 fb-1-1

* * NN with kinematics and isolation as input, s/b per event


H ->ZZ*/ZZ -> 4 leptons

Incase Higgs mass> 120 GeV

Backgrounds from tt, ZZ*,ZZ, Zbb


H ->ZZ*/ZZ -> 4e H ->ZZ*/ZZ -> 4

30 fb30 fb-1-1

H ->ZZ*/ZZ -> 4


Higgs boson mass, width and production cross section from H

->ZZ*/ZZ -> 4 leptons

H ->ZZ*/ZZ -> 4


H -> WW* -> ll

Around mH ~ 170 GeV,best channel

Backgrounds from WW, WZ, Wt, tt production Early Early

discoverydiscoverychannel !channel !


Summary of the Discovery Potential for the SM Higgs

Boson


Supersymmetry particlesSupersymmetry particlesLots of new particles (squarks, sleptons,…) predicted with masses in the range from 10’s of GeV’s up to several TeV range

Lightest SUSY particle stable: dark matter candidate ?

MET error

CMSCMS


SUSY - DiscoverySUSY - Discovery

4

1

( ) ( jets)eff T TM P P

backgrounds

SUSY600 GeV

squark

Dramatic event signatures ( cascade to LSP -> jets + Missing Et) and large cross section mean we will discover SUSY quickly, if sparticle mass is not very heavy


SUSY SUSY –– Squark/Gluino Mass Squark/Gluino Mass ““ReachReach””


Sparticle MassesSparticle Masses

endpoint in Mll

0 02 1

10 fb-1


55σσDiscovery potential for neutral MSSM Discovery potential for neutral MSSM HiggsHiggs


Discovery potential for charged Higgs bosons


ConclusionsConclusions

Expected Higgs boson searches in CMS: 10 fb-1: discovery in H->ZZ*/ZZ and H->WW* H→γγ possible 30-60 fb-1: discovery in H->(full SM mass range reached) observation of many other Higgs channels first measurement of Higgs boson properties

100-300 fb-1: observation of rare Higgs channels (WH,ttH,H->,...) precise measurement of Higgs boson properties

Expected SUSY searhes: - Low-mass SUSY visible almost immediately in many channels - Reconstruction of decay chains possible with the help of

endpoints

Full simulation results for many other channels and scenarios: - Extra dimensions - Alternative BSM signatures ...were not discussed


ThanksThanks


• backupbackup


Higgs productionHiggs production


Cross sectionCross section


Higgs decayHiggs decay

Guoming CHEN12015-5-4 The Capability of CMS Detector Chen Guoming IHEP, CAS 2008.10.24, Beijing.

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