# Presentation: 676161

## CMS: Hadronic Calorimetry &                                              Jet/       Performance

- V. Daniel Elvira                                                                        **Fermilab**
**(For the CMS Collaboration)**

- V. Daniel Elvira

- May 1-3, LHC 2003

## Outline

-  Detector descriptions and physics motivation
- The Hcal Test Beam 2002 experiment: noise, pulse shape, attenuation, single pion energy response & resolution
-  Monte Carlo studies on the HCal ability to measure jets, mass, missing transverse energy
- Monte Carlo production and Data Challenge 2004

- V. Daniel Elvira

- May 1-3, LHC 2003

## The CMS Detector

- HO

- HE ( extend to ||=3)

- HB  (||<1.3)

**The CMS Detector**

-            HF           (extend to ||=5)

- 8.6 m

- V. Daniel Elvira

- May 1-3, LHC 2003

## The CMS Physics

- H jet(H-> ****),     (m**H **< 120)      H-> ****  inclusive,                 qqH (H->WW*****-> ll****),
- qqH (H->****-> l ****-jet),
- WH-> l****** ******,  ttH (H->bb),                        qqH (H-> ****),  WH-> l**** bb

- qq (H -> ZZ*****/WW***** -> llll, ll****)  (120 < m**H **< 500)

- _Example:_   SM Higgs discovery channels

- The search for the Higgs boson, SUSY particles, new phenomena constitute the core of the CMS physics program

- HCal crucial  tool for jet and      measurements  (signature)

- V. Daniel Elvira

- May 1-3, LHC 2003

## HB Calorimeter (central)

- Sampling calorimeter:   brass (passive)  &  scintillator (active)
- Coverage:          ||<1.3
- Depth:               5.8 **int **(at =0)**          **segmentation:  x 
-  resolution:   ~ 120 %/                             0.087x0.087

**20****o**

- Completed & assembled

- 17 layers longitudinally,                      x  = 4 x 16 towers

- 

- V. Daniel Elvira

- May 1-3, LHC 2003

## HO Calorimeter (outer)

- Total number of **int**** **till the last sampling layer of HB is < 8
- HO: 2 scint. layers around first  layer (extend to~11 **int **)

- ~ 5% of a 300 GeV  energy is leaked outside the HB
- HO improves  resolution by ~10% at 300 GeV & linearity

- Test Beam 2002

**Ring 0**

**Ring 1**

**Ring 2**

- V. Daniel Elvira

- May 1-3, LHC 2003

## HE Calorimeter

**HE Calorimeter**

- Completed, assembled, HE-1 installed

- Sampling calorimeter:   brass (passive)  &  scintillator (active)
- Coverage:          1.3<||<3
- Depth:               10 **int **                **     **segmentation:   x 
-  resolution:   ~ 120%/                           0.087x0.087** **

**20****o**

- 19 layers longitudinally

- V. Daniel Elvira

- May 1-3, LHC 2003

## HF Calorimeter

**HF Calorimeter**

- Steel absorbers, embedded quartz fibres // to the beam Fast (~10 ns) collection of Cherenkov radiation.
- Coverage:          3<||<5              segmentation:   x 
- Depth:               10 **int                    **10**o** x 13  towers

- Fibre insertion finished by Nov 03

- V. Daniel Elvira

- May 1-3, LHC 2003

## HF Calorimeter

- HF used to tag forward jets in  qq (H -> ZZ*****/WW***** -> llll, ll****)  Higgs searches, to reduce QCD background by a factor of ~10.

- 120% at 50 GeV 20% at 400 GeV

- HF acceptance for tagging quarks of ET>30 GeV
- No q        1 q        2 q’s
-  0.47       0.46       0.07

- V. Daniel Elvira

- May 1-3, LHC 2003

## HCal 2002 Test Beam

- ECal 7x7 Crystal Matrix (movable)

- 2 HCal HB Modules

- HO Panels

- Aluminum Slab

**HCal 2002 Test Beam**

- beam

- Moving table

- Small scale experiment to demonstrate that HCal works: 49 ECal crystals, 144 HB channels, 16 HO channels.

- Over
- 100 Million
- Events!

- -:  225 GeV
- e-:  20,30,50,100 GeV
- -:  20,30,50,100,             300 GeV

- Read out with a 29.6 ns period

- V. Daniel Elvira

- May 1-3, LHC 2003

## HCal 2002 Test Beam

**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

- May 1-3, LHC 2003

## HCal 2002 Test Beam

**HCal 2002 Test Beam**

- HB Pulse out of the QIE            ( Charge Integration Electronics)

- 1/Response attenuation as the light travels longer distances to the QIE from central  towers

- Noise in HB

- V. Daniel Elvira

- May 1-3, LHC 2003

## HCal 2002 Test Beam

**HCal 2002 Test Beam**

- 225 GeV muon

- V. Daniel Elvira

- May 1-3, LHC 2003

## TB02 Simulation (OSCAR/G4 )

- Based on 1-5,000 **** events onto the ()=(6,2) tower of the HB and crystal 25 of the ECal matrix

**TB02 Simulation (****OSCAR/G4**** )**

**Crystal 25**

- 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)

- V. Daniel Elvira

- May 1-3, LHC 2003

## TB02 Simulation (OSCAR/G4 )

- 10 GeV electron

**HO**

**HB**

**ECal**

**Beam Line**

**TB02 Simulation (****OSCAR/G4**** )**

- 100 GeV pion

- V. Daniel Elvira

- May 1-3, LHC 2003

## TB02:  E/E and e/

**Pion peak**

**Muon background**

**Background subtracted pion peak**

******E**/E = 20.3%

**TB02: ******** ********E****/E and e/******

- 50 GeV pions

- Pions showering in the crystals

- Data energy resolution for 50 GeV pions (Ecal+HB, no HO)

- V. Daniel Elvira

- May 1-3, LHC 2003

## TB02:  E/E and e/

**TB02: ******** ********E****/E and e/******

- The agreement is excellent in all the energy range

- Shape difference: e/h (e.m. & nuclear x-sec), leakage......?

- Data systematic error analysis in progress

- Validate GEANT4 physics models

- Resolution

- Linearity

- V. Daniel Elvira

- May 1-3, LHC 2003

## Summary on TB Program

- Operation of 144 channels at 33.79 MHz
- Absolute calibration using beam/source
- Determination of pulse shape
- Measurement of  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,...more..., local synch in all channels, HB-HE boundary,  signal for calibration, remote monitoring & analysis

**Summary on TB Program**

- V. Daniel Elvira

- May 1-3, LHC 2003

## Jet &        Resolution

**Jet &        Resolution**

- PYTHIA + CMSIM + ORCA    single jets (R=0.5 cone algorithm)

- Squarks/gluinos of M~500 GeV decaying to jets +

- 39% at 20 GeV 12% at 100 GeV

- V. Daniel Elvira

- May 1-3, LHC 2003

## Mass Resolution

**Mass Resolution**

-     gg ->  -> hh -> 2**** + 2b,           m****=300 GeV, m**h**=125 GeV
-       ( Jet cone algo. R = 0.5 )                L=2x10**33** cm**-2** s**-1**

-     |****|,  R**b-jet ****                                      ****< 1.2, < 0.1****         ****< 2, < 0.1**** ****     <1.2, <0.3****            **

**No tracking correction**

**With tracking correction**

- V. Daniel Elvira

- May 1-3, LHC 2003

## DC04: Calib. & bkgnd.

- _Data Challenge 2004 (DC04):_ test data reconstruction chain, validate Monte Carlo,  optimize detector parameters, develop particle algorithms & calibration techniques, and perform  physics prospect studies.

- (a) _Calibration & background Samples:_
-   + jet for jet calibration
-  W (W -> l**** ) + N Jets
-  Standard one e/****  background process (N=1,2,3,4) +
-  Top quark pair production:   tt -> l****l****bb
-      - higher W p**T**,  jets,
-  QCD dijet background

- _Data Format:_ a Root Tree will be created from  DST files

- V. Daniel Elvira

- May 1-3, LHC 2003

## 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

- May 1-3, LHC 2003

## Summary

- 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

**Summary**

- V. Daniel Elvira

- May 1-3, LHC 2003

## Acknowledgments

**Acknowledgments**

- I would like to thank the members of the HCal and JetMET groups who contributed the material included in this talk

- V. Daniel Elvira

- May 1-3, LHC 2003