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CMS: Hadronic Calorimetry & Jet/ Performance

CMS: Hadronic Calorimetry & Jet/ Performance V. Daniel Elvira Fermilab. The CMS Detector. HF (extend to | h |=5). 8.6 m. HB (| h |<1.3). HO.

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CMS: Hadronic Calorimetry & Jet/ Performance

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  1. CMS: Hadronic Calorimetry & Jet/ Performance V. Daniel Elvira Fermilab V. Daniel Elvira

  2. The CMS Detector HF (extend to |h|=5) 8.6 m HB (|h|<1.3) HO HE ( extend to |h|=3) V. Daniel Elvira

  3. The CMS Physics The search for the Higgs boson, SUSY particles, new phenomena constitute the core of the CMS physics program HCal crucial for jet and measurements (signature) Example: SM Higgs discovery channels qq (H -> ZZ*/WW* -> llll, llnn)(120 < mH < 500) H jet(H-> gg), (mH < 120) H-> gg inclusive, qqH (H->WW*-> llnn), qqH (H->tt-> l t-jet), WH-> lngg, ttH (H->bb), qqH (H-> gg), WH-> ln bb V. Daniel Elvira

  4. HB Calorimeter (central) Sampling calorimeter: brass (passive) & scintillator (active) Coverage: |h|<1.3 Depth: 5.8 lint (at h=0)segmentation: f x h = p resolution: ~ (120 / + 4)% 0.087x0.087 17 layers longitudinally, f x h = 4 x 16 towers Completed & assembled 20o f V. Daniel Elvira

  5. HO Calorimeter (outer) Total number oflinttill the last sampling layer of HB is ~8. HO: 2 scint. layers around first m layer (extend to~11.8 lint ) Test Beam 2002 ~ 5% of a 300 GeV p energy is leaked outside the HB HO improves p resolution by ~10% at 300 GeV & linearity Ring 0 Ring 2 Ring 1 V. Daniel Elvira

  6. HE Calorimeter Sampling calorimeter: brass (passive) & scintillator (active) Coverage: 1.3<|h|<3 Depth: 10 lint (at h=0)segmentation: f x h = p resolution: ~ (120/ + 4)% 0.087x0.087 19 layers longitudinally 20o Completed, assembled, HE-1 installed V. Daniel Elvira

  7. HF Calorimeter Steel absorbers, embedded quartz fibres // to the beam Fast (~10 ns) collection of Cherenkov radiation. Coverage: 3<|h|<5 segmentation: f x h = Depth: 10 lint 10o x 13 h towers Fibre insertion finished by Nov 03 V. Daniel Elvira

  8. HF Calorimeter HF used to tag forward jets in qq (H -> ZZ*/WW* -> llll, llnn) Higgs searches, to reduce QCD background by a factor of ~10. HF acceptance for tagging quarks of ET>30 GeV No q 1 q 2 q’s 0.47 0.46 0.07 120% at 50 GeV 20% at 400 GeV V. Daniel Elvira

  9. HCal 2002 Test Beam Small scale experiment to demonstrate that HCal works: 49 ECal crystals, 144 HB channels, 16 HO channels. HO Panels ECal 7x7 Crystal Matrix (movable) Over 100 Million Events! beam m-: 225 GeV e-: 20,30,50,100 GeV p-: 20,30,50,100, 300 GeV Moving table Read out with a 29.6 ns period Aluminum Slab 2 HCal HB Modules V. Daniel Elvira

  10. HB L s) 16 ) HB L s) 16 ) beam ADC counts beam HB L s) 100 GeV electron 16 ) 225 GeV muon beam h 300 GeV pion ADC counts f h f h f HCal 2002 Test Beam 97% of energy contained in a 3x3 crystal matrix 99% of energy contained in a 5x5 HB tower matrix V. Daniel Elvira

  11. (f,h)=(1,1) HB Pedestal sigma distribution mean : 0.875 ADC = 260 MeV 300 GeV pions Time(ns) Att. (Arbit. Units) Attenuation ~ 50% h HCal 2002 Test Beam Noise in HB HB Pulse out of the QIE ( Charge Integration Electronics) Response attenuation as the signal travels longer distances to the QIE from high h towers V. Daniel Elvira

  12. beam HO h f HO Signal Pedestal Subtracted beam HB Pedestal Distribution h f HCal 2002 Test Beam Measurement of HO muon signal for RPC trigger (Goal: use the HO as part of muon trigger) 225 GeV muon V. Daniel Elvira

  13. 76543210 f 0 6 15 h TB02 Simulation (OSCAR/G4 ) An accurate Monte Carlo simulation is critical: detector design & calibration, data analysis Validation of GEANT4/OSCAR by June03 for M.C. production towards DC04 & physics TDR) Crystal 25 Based on 1-5,000 p- events onto the (h,f)=(6,2) tower of the HB and crystal 25 of the ECal matrix V. Daniel Elvira

  14. HO ECal Beam Line HB TB02 Simulation (OSCAR/G4 ) Angle view of the full TB02 detector 10 GeV electron HO ECal 100 GeV pion Beam Line HB V. Daniel Elvira

  15. TB02: psE/E and e/p 50 GeV pions Data energy resolution for 50 GeV pions (Ecal+HB, no HO) Pions showering in the crystals Background subtracted pion peak Muon background Pion peak sE/E = 20.3% V. Daniel Elvira

  16. TB02: psE/E and e/p Resolution Linearity Shape difference: e/h (e.m. & nuclear x-sec), leakage……? The agreement is excellent in all the energy range Data systematic error analysis in progress Validate GEANT4 physics models V. Daniel Elvira

  17. Summary on TB Program • Goals for the 2002 HCal testbeam, • Operation of 144 channels at 33.79 MHz • Absolute calibration using beam/source • Determination of pulse shape • Measurement of h attenuation • Determination of Layer-0 weighting • Measurement of muon signal (HO) for RPC trigger • Control of HV, front end, and moving source • have been met! Move on to TB03... Repeat TB02 tests,…plus…, local synch in all channels, HB-HE boundary, m signal for calibration, remote monitoring & analysis V. Daniel Elvira

  18. Jet & Resolution Squarks/gluinos of M~500 GeV decaying to jets + PYTHIA + CMSIM + ORCA single jets (R=0.5 cone algorithm) 39% at 20 GeV 12% at 100 GeV V. Daniel Elvira

  19. Mass Resolution gg -> f -> hh -> 2g + 2b, mf=300 GeV, mh=125 GeV ( Jet cone algo. R = 0.5 ) L=2x1033 cm-2 s-1 No tracking correction With tracking correction |h|, DRb-jet < 1.2, < 0.1< 2, < 0.1 <1.2, <0.3 V. Daniel Elvira

  20. DC04: Calib. & bkgnd. Data Challenge 2004 (DC04):test data reconstruction chain, validate Monte Carlo, optimize detector parameters, develop particle algorithms & calibration tecniques, and perform physics prospect studies. Data Format:a Root Tree will be created from DST files • (a) Calibration & background Samples: •  + jetfor jet calibration • W (W -> l ) + N Jets • Standard one e/m background process (N=1,2,3,4) + • Top quark pair production:tt -> llbb • - higher W pT, jets, • QCD dijetbackground V. Daniel Elvira

  21. DC04: Physics • (b) Physics Samples: • Higgs Production • qq H ( H  lljj ) for optimization of HF and TB studies, forward jet tagging, • WLWL  WLWL scattering • - qq  WWqq  WWqq  ljjjj strong dynamics for EW symmetry breaking, jets, , CompHEP-PYTHIA comparisons • Z´ search • qq  Z´  qq (useful for energy resolution studies) • SUSY particle search • gluino/squark  energetic central jet, large V. Daniel Elvira

  22. Summary • HB and HE hadronic calorimeters completed and assembled. HF fibre insertion finished by the end of 2003 • Goals for the HCal 2002 test beam experiment have been met, moving on to TB03 program • Looking forward to M.C. production & DC04 for simulation and reconstruction validation, detector optimisation, physics prospects V. Daniel Elvira

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