1. LCWS06@IIScCMS Calorimeter1 Understanding the Performance of CMS Calorimeter Seema Sharma,TIFR (On behalf of CMS HCAL)

2. LCWS06@IIScCMS Calorimeter2

3. LCWS06@IIScCMS Calorimeter3 HCAL : Scintillator-Brass Sampling Calorimeter 2-3 longitudinal samplings from 17-19 layers of Scnt. ECAL: PbWO 4 Crystal Homogeneous Calorimeter of ~26 Χ 0

4. LCWS06@IIScCMS Calorimeter4 TB2004 Setup  2 wedges of HCal Barrel  2 slices of HCal endcap  6-trays of HO for 3 rings  Mock-up of CMS magnet  Tail catcher iron  7 X 7 ECal crystal matrix  Mock-up of material between ECal and HCal  Beam line trigger counters

5. LCWS06@IIScCMS Calorimeter5 HCAL on a Table HB HE HO ECAL pivot beam Pivot of table = IP at LHC A phi slice of CMS HCAL

6. LCWS06@IIScCMS Calorimeter6 ECAL Module

7. LCWS06@IIScCMS Calorimeter7 Hadron Calorimeter HO VM HB1 HB2

8. LCWS06@IIScCMS Calorimeter8 Readout Configuration

9. LCWS06@IIScCMS Calorimeter9 Beam Line Counters WC-A WC-B WC-C S1 S4 S3 S2

10. LCWS06@IIScCMS Calorimeter10 80 GeV/c SCI_VLE CK 2 CK 3 WC A,B,C HCAL ECAL V3,V6 VM P-ID: CK2- electron CK3- pion / kaon / proton V3, V6, VM – muon VLE tag against punchthrough muon WC single hit to reject interaction in beam line Beam Line at H2

11. LCWS06@IIScCMS Calorimeter11 Data Sets

12. LCWS06@IIScCMS Calorimeter12 Done using Co 60 source at the tip of a stainless steel wire. With the source at η boundaries, adjacent tiles receive some signal. Contributions from adjacent tiles are added. Source Calibration Source position

13. LCWS06@IIScCMS Calorimeter13 Calibration constant corresponds to a least square fit across the tile. An iterative procedure is followed to get final calibration constants. Source Calibration (continued…) Source position

14. LCWS06@IIScCMS Calorimeter14  Fit the pedestal distribution with a Gaussian.  Fit muon signal with a convolution of Landau and Gaussian distributions.  Float the relative contribution of the pedestal.  The peak of the fitted LandauGauss function is used as the calibration constant. Calibration with Muons at 150 GeV

15. LCWS06@IIScCMS Calorimeter15 Correlation Between Source and Muon Calibration A straight line fit through all the points gives χ 2 /ndf of 18. Some correlation is observed between the calibration constants obtained using the two methods.

16. LCWS06@IIScCMS Calorimeter16 300 GeV150 GeV 100 GeV 30 GeV HB ECAL HB  e-e- Energy Measurement

17. LCWS06@IIScCMS Calorimeter17 Comparison with GEANT4 Simulation (LHEP)

18. LCWS06@IIScCMS Calorimeter18 Energy Measurements at Low Energies

19. LCWS06@IIScCMS Calorimeter19 LHEP without scintillation saturation effect (Birks’ law) shows a reasonable agreement with data for EC+HB combined system. Need more beam clean up and better understanding of systematic errors before making more definitive conclusion, especially HB alone data, (not shown today) … proton pions π/e Response

20. LCWS06@IIScCMS Calorimeter20 Energy Resolution 0.92 GeV measured Larger noise than HB1 (0.4GeV in 3x3) because of individual layer readout in HB2.

21. LCWS06@IIScCMS Calorimeter21 Two G4 physics models show difference at high energy. Event selection – MIP in ECAL. Longitudinal Shower Profile

22. LCWS06@IIScCMS Calorimeter22 Summary  Test beam data were taken during 2004 with the final(?) electronics modules.  A large data set was collected with pions and electrons with the energies in the range 3-300 GeV with proper particle identification especially at low energies.  Test beam results are compared with the GEANT4 simulations. LHEP physics list describes the data most closely.  Energy response and resolution obtained from various physics lists match closely and only difference is seen in longitudinal shower profiles at high energies.  HCAL team plans to continue with testing the calorimeter modules with improved VLE beam and better PID.