ECAL and HCAL Simulation Status Rick Wilkinson Fabio

ECAL and HCAL Simulation Status Rick Wilkinson Fabio Cossutti

Simulation l Sim Hit: One ns of energy deposit in an active volume l Done by GEANT 4 (Sunanda Banerjee) l Depends strongly on geometry modeling l ECAL (Paolo Meridiani) l HCAL (Jeremy Mans)

Digitization l l l Digitization includes: pulse shape, pileup, amplification, noise, ADC encoding, trig prims, zero suppression CMSSW Digitization has details not in ORCA Common framework for all systems (Wilkinson) ECAL (Cossutti, P. Govoni, Wilkinson) HCAL (Fedor Ratnikov, Wilkinson) Preshower (Chia-Ming Kuo)

Digitization using Calibration? l Allows added realism l Make l hot channels hot, noisy channels noisy Allows blind test of calibration techniques l Simulate the data with one set of constants l Use derived calibration for reconstruction

Noises Pedestal ECAL Barrel 200 ADC ECAL Endcap 200 ADC HCAL HF Pedestal width 1. 26 ADC (40 Me. V) 2. 87 ADC (150 Me. V) 5 ADC 0. 56 ADC (0. 75 Ge. V) (0. 1 Ge. V) 2 ADC 0. 3 ADC (0. 75 Ge. V) (0. 14 Ge. V) Gain Width 0. 3 % Rear non-uniformity Front done in OSCAR 0. 3 % 0 0

Photostatistics Photoelectrons / Ge. V 1 / sqrt(N) ECAL Barrel 2250 2. 1% / sqrt(E) ECAL Endcap 1800 2. 4% / sqrt(E) Photoelectrons / Ge. V Sampling Frac. HCAL (HB) 17 117 HCAL (HE) 17 117 HCAL (HO) 18. 4 217 HCAL (HF 1) 2. 84 1 HCAL (HF 2) 2. 09 1 178

ECAL Digitization: Details (Fabio Cossutti) l Gain Switching (including hysteresis) l Calibration Interface (Shahram Rahatlou) l No database access yet, just interface l Uses gain ratios, pedestals, & widths l Correlated Noise l Implemented with a global correlation matrix l Currently a unit matrix

HCAL Digitization: Details l Layer 0: Weighting done by GEANT 4 (Banerjee) l Calibration Interface (Fedor Ratnikov) l l l Time Slew (Jeremy Mans) l l Fetch pedestals, gains, & noise For each of four capacitors in channel Small signals delayed by ~10 ns Correlated Noise l l Effect is big in HCAL (Michal Szleper) Not simulated, but infrastructure exists

Trig Prims ECAL Trig Prims (Ursula Berthon) l HCAL Trig Prims (Jeremy Mans) l

Zero Suppression l ECAL Selective Readout (Philippe Gras) l l l Trig prim > 5 Ge. V: read all 25 x 25 crystals Trig prim > 2. 5 Ge. V: read 5 x 5 crystals Otherwise 90 Me. V threshold in barrel l 450 Me. V in endcap l l HCAL Zero Suppression (Jeremy Mans) l l Pedestal-subtracted amplitudes Can store both suppressed & unsuppressed digis

Validation ECAL l Hits (Xingtao Huang) l Digis (F. Cossutti) l Rec. Hits (Chiara Rovelli) • 30 Ge. V photons • 400 Ge. V photons • 60 Ge. V pions • Neutrinos (for noise) HCAL • 100 Ge. V Pions • Hits (Salavat Abdullin) Abdullin • Digis (Dmitri Konstantinov) Konstantinov

ECAL Simulation Plans l New Geometry (Brian Heltsley) l Handles material behind the crystals better l Important for HCAL l Study shower shape l ~1% l discrepancy, maybe Cerenkov Energy deposit inside APD