1 HCAL Upgrade TP simulation studies Jane Nachtman (Iowa) – for the HCAL group Trigger Upgrade meeting April 28, 2010

Today’s status talk: l Simulation work for HCAL Upgrade TP’s è A tremendous amount of work has been done by the HCAL and simulation groups è I will quickly summarize studies and status l Critical issue – getting software updated and integrated in to a standard CMSSW release è Many technical issues 2

Summary of HCAL Upgrade simulation l Simulation of proposed hardware upgrades for HCAL è Provide input to hardware specifications è Physics justification è Trigger studies l Large effort from many people over the past ~1 year: è SiPM simulation/implementation/studies (FNAL,Caltech) è Front-end amplifier (QIE10) simulation/testing (Princeton) è Multi-depth SimHits simulation/studies (Minnesota) è Upgrade TP code (Princeton) è Energy re-weighting (DESY) è Implementation in CMSSW (FNAL) l Many results based on this work have been presented over the past year 3

SiPM Simulation (FNAL, Caltech, Minn.) l HPD’s in HCAL proposed to be replaced by SiPM’s l SiPM simulation is integrated into CMSSW è Basic SiPM response, time shaping, recovery model è See details in Jake Anderson’s talk è Various devices have been simulated to search for optimal choice for HCAL needs è Currently implemented in 3_5_X: Hamamatsu and Zecotek devices in appropriate channels. à Flag can make HO all HPD, all SiPM, or (hardcoded) current configuration. à SiPM gains also in 3_5_X MC conditions db l SiPM simulation -- rapid progress driven by HO needs, but can be extended to all-HCAL studies 4

HCAL Multi-depth simulation and upgrade TP l Using SiPM’s allows readout of multiple depths in each tower l Minnesota simulation -- produce SimHits for each layer, then combine into user-defined depth (four depths, configurable layers/depth) (CMSSW 2_2_5) l Documented at : è Studies of, eg, impact on L1 trigger quantities have been done for possible configurations of layers l Princeton group – create a new “upgrade” TP, compatible with current TP è code in UserCode/eberry/Producers/HcalSLHCTrigPrimDigiProducer/ è An HcalSLHCTriggerPrimitiveSample has:  8 bits of “compressed et”  8 bits of “fine grain” – usage to be defined (current TP has 1)  8 bits of “isolated compressed et” (current TP has 0) 5

Layer energy re-weighting l DESY group– use longitudinal resolution to re-weight based on EM (high energy density) and HAD parts of shower l Found improved resolution for 4-depth readout : 6 4-depth segment. 6-depth Channel breakdown study -- 6-depth segmentation gives better results (from Matthias Stein’s talk at DESY SiPM workshop 2/22/2010)

Energy Compensation from Layer Weighting – validate using testbeam data Weights from DESY study ( ) applied to test beam(TB09) data by Halil Saka (Princeton) Plots show energy before (histo) and after re-weighting(shaded), for various incident pion beam energies

Resolution in Testbeam data l Resolution improved by reweighting 8 s/m s/m = S/sqrt(E) + N/E + C (MAPD) (HPD)

CMSSW Implementation l Recent work (from Sunanda and simulation group): è Flexibility in grouping in geometry and topology (also useful for testbeam studies) è Add Cerenkov signals – change in data format -- in CMSSW 3_7_X Memory check for pileup simulation use Mixing module Memory usage is monitored with various numbers of pileup events Up to checked, memory ok Many technical issues in integrating HCAL upgrade simulation Implications of new geometry Conditions database Maintain compatibility with current detector Memory usage for 200 ttbar events with 200 MinBias pileup events

summary l A great deal of work has been done on HCAL upgrade simulation by many people l Various software packages have been written/tested è SiPM, QIE10, multi-depth layer simulation, upgrade TPG, pileup memory è Studies with existing packages have produced useful results è Various (some old) versions of CMSSW l Main effort – CMSSW integration – has begun è Technical issues – geometry, conditions, many parts of the code need to change 10

Extra slides

QIE10 Simulation work l Signal-to-Noise ratio is currently hardwired in the HCAL front-end QIE electronics è QIE noise will remain the same, large SiPM signal would have to be attenuated down to the HPD signal size è QIE dynamic range will change l Simulation of QIE10 coded and studied (Princeton group) Fractional quantization error vs Energy (Gev)

13 Upgrade HCAL TP Details HcalTriggerPrimitiveDigi Identified by an HcalTrigTowerDetId Contains multiple HcalTriggerPrimitiveSamples with bit-wise information An HcalTriggerPrimitiveSamples has:  8 bits of “compressed et”  1 bit of “fine grain” energy information HcalSLHCTriggerPrimitiveDigi Identified by an HcalTrigTowerDetId Contains multiple HcalSLHCTriggerPrimitiveSamples with bit-wise information An HcalSLHCTriggerPrimitiveSample has:  8 bits of “compressed et”  8 bits of “fine grain” – usage to be defined (1 in current)  8 bits of “isolated compressed et” (0 in current)

CMSSW Implementation (from Sunanda) l Current/latest work: è Flexibility in grouping in geometry and topology (also useful for testbeam studies) è Add Cerenkov signals – change in data format -- in CMSSW 3_7_X Memory check for pileup simulation use Mixing module ( improved in CMSSW 3_0_X by E. Becheva and C. Charlot ) Now has playback option -- look at all the hits and history (not saved with the event) for special studies Memory usage is monitored by varying number of pileup events (done with bunch spacing of 25 ns and with 5 pre- and 3 postbunches) Study using CMSSW version 3_4_X (3_6_X) Up to checked, memory ok

Energy Fraction + Weighting Factors (Fluka) PRELIMINARY  Energy fractions as expected: The bigger the energy density, the bigger the em fraction Channel 3 Results obtained from a MC data sample of  at 30 GeV.  Weighting factors as expected: The bigger the energy density, the smaller the weights PRELIMINARY Channel 3 Matthias Stein