HCAL Digitization Rick Wilkinson 1

CMSSW HCAL Simulation Three gains are used as input –Calibration (GeV/fC) From DB gain, by channel –Electronics (fC/photoelectron) One parameter per subsystem –Sampling factor (GeV / deposited GeV) One parameter per ring These are used to calculate p.e./deposited GeV –All gains cancel themselves out in the chain So we should always reconstruct the correct energy, even when gains aren’t quite appropriate. –Signal/noise will be affected, though. 2

Silicon Photomultipliers 132 devices in HO now Saturate as a function of effective # of pixels. # of pixels = area of fibers * pixel density Long recovery time Better S/N, so can be used for muon ID 3

Data Mixing We re-run the signal digitization inside the DataMixer –Pileup digis are used as pedestals –Random noise added where no pileup digi –Avoids roundoff error Tested heavily – 4

Correlated Noise No correlations used now Under development: using full 10x10 correlations for each channel –To save time, a processed matrix is stored in DB, not the original covariance matrix –Handled fully in Conditions system. 5

Plans All SiPM code is queued for 3_5_X. –Still need an MC conditions tag with SiPM gains –Then some final tuning and testing. To do –Correlated noise –Handle hits in glass windows of HF PMTs –Database of SiPM configuration –Get electronics gain (QIE) from database 6