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Particle identification in ECAL. Yuri Kharlov, Alexander Artamonov IHEP, Protvino CBM collaboration meeting 28.09.2007. PID methods applicable for ECAL. The aim of ECAL PID is to discriminate and e from anything else Charged track matching
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Particle identification in ECAL Yuri Kharlov, Alexander Artamonov IHEP, Protvino CBM collaboration meeting 28.09.2007 ECAL PID
PID methods applicable for ECAL The aim of ECAL PID is to discriminate and e from anything else • Charged track matching • Reject (for ) or identify (for e) ECAL clusters produced by charged tracks • Flight time measurement • Reject ECAL clusters produced by slow particles (mainly heavy hadrons) • Transverse shower shape • Discriminate electromagnetic and hadronic showers • Longitudinal shower profile • Discriminate electromagnetic and hadronic showers ECAL PID
Flight time from target to ECAL (12 m) Neutral hadrons contribute to photon spectrum mainly at E<2 GeV Significant background is expected from antineutrons at 1.8 GeV Time resolution t=1 nsis sufficient for rejection of K0 and neutrons ECAL PID
Longitudinal profile of electromagnetic shower (PDG) ECAL PID
Prototype of “Two-Sections” ECAL Module 20X0 = 10X0 + 10X0 Two channel PMT based on PM FEU-115M dynode system 110 Lucite prism for uniform light mixing 450 Total radiation length = 20Xo. Number of layers = 85 Lead plate thickness = 1.3 mm Scintillator plate thickness = 4.0 mm Scintillator –Polystyrene + 1.5%PT + 0.05% POPOP Wave Length Shifting Fibers – Y11 Light from the first half of calorimeter (preshower) was collected to one anode and light from the second half to another. V.Brekhovskikh, V.Rykalin 21 September 2006 ECAL PID
2-segment module design Separate light collection to 2-channel PMT V.Brekhovskikh, V.Rykalin 21 September 2006 ECAL PID
Beam measurements of 2-segment module All calorimeter Preshower Accepted electrons (84%) Rejected pions (93%) V.Brekhovskikh, V.Rykalin 21 September 2006 ECAL PID
Simulation model • 1 module with 160 layers (Pb 0.7 mm + Sci 1.0 mm) • Total radiation length: 20X0. • 20 longitudinal segments, each of 8 layers • Various combinations of energies deposited in different segments allow to optimize longitudinal segmentation ECAL PID
Edet vs Segment number: 5 GeV Photons Hadrons ECAL PID
Edet vs Segment number : 10 GeV Photons Hadrons ECAL PID
Edet vs Segment number : 15 GeV Photons Hadrons ECAL PID
Longitudinal profile: Photons 5 GeV 10 GeV ECAL PID
Longitudinal profile: Hadrons 5 GeV 10 GeV ECAL PID
Longitudinal profile: Muons 5 GeV 10 GeV ECAL PID
E1/E2, 5 GeV (1X0+19X0) ECAL PID
E1/E2, 5 GeV (2X0+18X0) ECAL PID
E1/E2, 5 GeV (3X0+17X0) ECAL PID
E1/E2, 5 GeV (4X0+16X0) ECAL PID
Identification probabilities (1X0+19X0) S/B=3.5 ECAL PID
Identification probabilities (2X0+18X0) S/B=3 ECAL PID
Identification probabilities (3X0+17X0) S/B=2 ECAL PID
Identification probabilities (4X0+16X0) S/B=1.5 ECAL PID
To do • 3-segment module: the optimal segmentation to be found • Realistic momentum distribution of incoming particles • Realistic particle multiplicity to be studied • Track-ECAL matching and optimization of the matching distance for charged particle rejection • Simulation of realistic TOF measurement in ECAL and optimization of ECAL-TOF cut for heavy hadron rejection • Photon identification efficiency and hadron contamination of the photon spectrum in central HI collisions ECAL PID