Guoming CHEN The Capability of CMS Detector Chen Guoming IHEP, CAS , Beijing

Guoming CHEN2 CMS B field: 4T

Guoming CHEN 3 CMS η coverage

Guoming CHEN 4 Inner Tracker – All Si 5.4 m Outer Barrel –TOB- Inner Barrel –TIB- End cap –TEC- Pixel 2,4 m Inner Disks –TID- 210 m 2 of silicon sensors 6,136 Thin detectors (1 sensor) 9,096 Thick detectors (2 sensors) 9,648,128 electronics channels

Guoming CHEN5 Vertex detector: Si pixel space resolution: 10 μm 10 μm

Guoming CHEN6 Si Strip TRACKER

Guoming CHEN7 Momentum resolution

Guoming CHEN8 Material budget

Guoming CHEN9 ECAL – PbWO Crystals

Guoming CHEN10

Guoming CHEN11 ECAL Test Beam Module

Guoming CHEN12 Electron and Gamma Energy Resolution

Guoming CHEN13 CMS - HCAL Back-flange 18 Brackets 3 Layers of absorber Made of brass and scintillator. Radiation tolerant scintillator and HPD photo transducer works in 4T field.

Guoming CHEN14 Jet energy resolution

Guoming CHEN15 CMS Muon System Three types of gaseous detectors Drift Tubes in barrel region Drift Tubes in barrel region 4 stations interleaved with iron return yoke 4 stations interleaved with iron return yoke Cathod Strip Chambers in endcap regions Cathod Strip Chambers in endcap regions 4 stations interleaved with iron return yoke 4 stations interleaved with iron return yoke Up to |  | < 2.4 Up to |  | < 2.4 Resistive Plate Chambers in both barrel and endcaps Resistive Plate Chambers in both barrel and endcaps precise bunch crossing ID for Trigger precise bunch crossing ID for Trigger Up to |  | < 2.1 Up to |  | < 2.1

Guoming CHEN16 Barrel MUCH

Guoming CHEN EndcapMUCH

Guoming CHEN18 Muon momentum resolution

Guoming CHEN19 Particle ID

Guoming CHEN 20 Trigger table: 2x10 33 cm -2 s -1 TriggerThreshold (GeV ) Rate (Hz) Cuml. rate (Hz) Inclusive electron Di-electron17134 Inclusive photon Di-photon 40, Inclusive muon Di-muon7472 Inclusive tau-jet Di-tau-jet jet * E T miss 180 * jet OR 3-jet OR 4-jet 657, 247, Electron * jet 19 * Inclusive b-jet Calibration etc TOTAL105

Guoming CHEN21 CMS installation

Guoming CHEN22 Beampipe installation before Closure

Guoming CHEN23 Final Closure

Guoming CHEN24 Cosmic ray test

Guoming CHEN25 Collimator Spray

Guoming CHEN26 Tracker Alignment with cosmic rays CRUZET4 TIB Transverse impact point – using cosmics to align tracker

Guoming CHEN27 Summary CMS has no dead region from -5 to 5 of ηCMS has no dead region from -5 to 5 of η CMS emphasizes muon, gamma and electron measurementCMS emphasizes muon, gamma and electron measurement CMS was produced, installed and tested. Every piece works well, it is ready for physicsCMS was produced, installed and tested. Every piece works well, it is ready for physics

Guoming CHEN28 Higgs search New !

Guoming CHEN29 Probability of Higgs mass Jens Erler

Guoming CHEN30 H → γγis the first channel at CMS

Guoming CHEN31 Discovery potential of H->  SM Significance for SM Higgs M H =130 GeV for 30 fb -1 * * NN with kinematics and  isolation as input, s/b per event

Guoming CHEN32 H ->ZZ*/ZZ -> 4 leptons Incase Higgs mass> 120 GeV Backgrounds from tt, ZZ*,ZZ, Zbb

Guoming CHEN33 H ->ZZ*/ZZ -> 4e H ->ZZ*/ZZ -> 4  30 fb -1 H ->ZZ*/ZZ -> 4 

Guoming CHEN34 Higgs boson mass, width and production cross section from H ->ZZ*/ZZ -> 4 leptons H ->ZZ*/ZZ -> 4 

Guoming CHEN35 H -> WW * -> l l Around m H ~ 170 GeV, best channel Backgrounds from WW, WZ, Wt, tt production Earlydiscovery channel !

Guoming CHEN36 Summary of the Discovery Potential for the SM Higgs Boson

Guoming CHEN37 Supersymmetry particles Supersymmetry particles   Lots 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 CMS

Guoming CHEN38 SUSY - Discovery backgrounds SUSY 600 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

Guoming CHEN39 SUSY – Squark/Gluino Mass “ Reach ”

Guoming CHEN 40 Sparticle Masses endpoint in M ll 10 fb -1

Guoming CHEN41 5σDiscovery potential for neutral MSSM Higgs

Guoming CHEN42 Discovery potential for charged Higgs bosons

Guoming CHEN43 Conclusions Expected Higgs boson searches in CMS: 10 fb -1 : discovery in H->ZZ*/ZZ and H->WW* H → γγ possible fb -1 : discovery in H->  (full SM mass range reached) observation of many other Higgs channels   first measurement of Higgs boson properties 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

Guoming CHEN44 Thanks

Guoming CHEN45 backup backup

Guoming CHEN46 Higgs production

Guoming CHEN47 Cross section

Guoming CHEN48 Higgs decay

Guoming CHEN49

Guoming CHEN50 Sparticles mass resolution