UTA GEM DHCAL Simulation Jae Yu * UTA DoE Site Visit Nov. 13, 2003 (*On behalf of the UTA team; A. Brandt, K. De, S. Habib, V. Kaushik, J. Li, M. Sosebee, A. White) Introduction GEM Geometry Implementation Single Pion Study for GEM performances GEM Analog Mode GEM Digital Mode Single Pion EFA Studies Summary

Nov. 13, 2003Status of DHCAL Simulation, J. Yu2 Introduction LC physics topics require excellent jet energy and angular resolutions Energy flow algorithm is one of the solutions Large number of readout channel will drive up the cost for analogue style energy measurement  Digital HCAL Tracking calorimeter with high gain sensitive gap –GEM is one such detector technology Simulation effort to understand detector progressed along with prototype development –Thanks to the support from LCRD and ADR

Nov. 13, 2003Status of DHCAL Simulation, J. Yu3 UTA GEM Simulation LC Physics Events: Pandora – Phythia Use Mokka as the primary tool –Kept the same detector dimensions as TESLA TDR –Replaced the HCAL scintillation counters with GEM ( 18mm SS + 6.5mm GEM, 1cmx1cm cells ) Single Pions used for performance & EFA studies –5 – 100 GeV single pions –Analyzed them using ROOT

Nov. 13, 2003Status of DHCAL Simulation, J. Yu4 TESLA TDR Geometry Ecal – Electromagnetic Calorimeter Material: W/G10/Si/G10 plates (in yellow) 1mm W absorber plates 0.5 mm thick Si, embeded 2 G10 plates of 0.8 mm each Hcal – Hadronic Calorimeter Material: 18 mm of Fe 6.5 mm of Polystyrene scintillator (in green)

Nov. 13, 2003Status of DHCAL Simulation, J. Yu5 UTA Double GEM Geometry 3.4 mm ArCO 2 GEM 3.1 mm Simple GEM Detailed GEM Cu Kapton ArCO 2 G mm Detailed GEM 75GeV  =0.80  0.007MeV =0.81  0.008MeV Simple GEM 75GeV  25.2sec/event for Simple GEM v/s 43.7 sec/event for Detailed GEM

Nov. 13, 2003Status of DHCAL Simulation, J. Yu6 Energy Deposit for 10 GeV Pions (GEM) f EM >=0.85 Remaining Total f HC >=0.85

Nov. 13, 2003Status of DHCAL Simulation, J. Yu7 GEM-Digital: E live vs # of hits for π -

Nov. 13, 2003Status of DHCAL Simulation, J. Yu8 GEM Cell Occupancies ~85% single hit ~15% >1 hit ~74% single hit ~26% >1 hit Number of cells with higher number of hits increase w/ E

Nov. 13, 2003Status of DHCAL Simulation, J. Yu9 N vs Layer Energy Deposit/Ncells vs Layers for 50 GeV Pions E vs Layer

Nov. 13, 2003Status of DHCAL Simulation, J. Yu10 Extraction of of dE/dN

Nov. 13, 2003Status of DHCAL Simulation, J. Yu11 EM-HAD Relative Weighting Factor To compensate the response differences between ECAL and GEM HCAL responses a procedure to normalize them had to be introduced –E Live =  E EM + W  gE HAD (g:GEM Intrinsic gain) –Obtained the relative weight W using two Gaussian fits to EM only v/s HAD only events –Perform linear fit to Mean values as a function of incident pion energy –Extract ratio of the slopes  Weight factor W –E = C* E Live

Nov. 13, 2003Status of DHCAL Simulation, J. Yu12 GEM – Relative Weights Analog Digital

Nov. 13, 2003Status of DHCAL Simulation, J. Yu13 GEM-Digital: Live Energy 50 GeV π -

Nov. 13, 2003Status of DHCAL Simulation, J. Yu14 GEM – Normalized Response Analog: 2.4% Digital:2.6%

Nov. 13, 2003Status of DHCAL Simulation, J. Yu15 Converted energy: 50 GeV π - Analog Digital Fits are Landau + Gaussian

Nov. 13, 2003Status of DHCAL Simulation, J. Yu16 Resolutions Digital GEMAnalog GEM

Nov. 13, 2003Status of DHCAL Simulation, J. Yu17 EF Technique C2C2 C3C3 C5C5 C7C7 C4C4 C6C6 C1C1 Normal Calorimetric Method: p2p2 p3p3 p5p5 p7p7 Energy Flow Method: Only susceptible part to Shower statistical fluctuation

Nov. 13, 2003Status of DHCAL Simulation, J. Yu18 Charged particle energy subtraction based on track-cluster association is important to EFA The algorithm must work well with single particle case Pions  E π-  = 7.5 GeV chosen for study Studied the energy distribution of pions in jet events Find the centroid of the shower ( HCAL ) using –Energy weighted method –Hits weighted method –Density weighted method Match the extrapolated centroid with TPC last layer hit to get Δ  and Δφ distribution Energy Flow Studies Using π -

Nov. 13, 2003Status of DHCAL Simulation, J. Yu19 Energy Weighted Method Hit Weighted Method Density Weighted Method Calorimeter Centroid Determination

Nov. 13, 2003Status of DHCAL Simulation, J. Yu20 Event Displays E  =50 GeV 6 jets Single 

Nov. 13, 2003Status of DHCAL Simulation, J. Yu21 Neutral particles Number of charged and Neutral particles Charged: e ,  , K  ~12 ~6

Nov. 13, 2003Status of DHCAL Simulation, J. Yu22  R of all the particles relative to quark  R flattens out after 0.3

Nov. 13, 2003Status of DHCAL Simulation, J. Yu23  E weighted vs Numerical Mean) E  = 50 GeV 1cm x 1 cm cells E weighted =-3.1x10 -5  =1.1x10 -2 Numerical Mean =-1.2x10 -3  =2.5x10 -2 Analog seems to be better than digital but not by significant factor

Nov. 13, 2003Status of DHCAL Simulation, J. Yu24  GeV π - Energy Weighted Hit Density Weighted Bug???

Nov. 13, 2003Status of DHCAL Simulation, J. Yu25 Summary Made a marked progress thanks to the LCRD and ADR support Completed single  GEM DHCAL performance studies –Initial study documented in Habib’s MS thesis –More detailed and refined study being completed by Kaushik –Analog resolution seems to be worse compared to other detector technology due to large fluctuation in initial ionization electrons –Digital, however, performance is comparable to other analog technologies Released our Pandora – Phythia ASCII and other analysis packages to LC software group per their request

Nov. 13, 2003Status of DHCAL Simulation, J. Yu26 EFA studies in progress –Study track – cluster association and energy subtraction using single pion  Three methods being investigated –Study typical distance between charged particles within the jet –Determine necessary resolving power for realistic situation Prepare for larger scale prototype, cosmic ray stack and TB simulation Development of analysis software Continued and increased support is critical to make the next quantum jump