ECAL PID1 Particle identification in ECAL Yuri Kharlov, Alexander Artamonov IHEP, Protvino CBM collaboration meeting

ECAL PID2 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 PID3 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 ns is sufficient for rejection of K 0 and neutrons

ECAL PID4 Longitudinal profile of electromagnetic shower (PDG)

ECAL PID5 Prototype of “Two-Sections” ECAL Module Two channel PMT based on PM FEU- 115M dynode system X 0 = 10X X 0 Total radiation length = 20 X o. Number of layers = 85 Lead plate thickness = 1.3 mm Scintillator plate thickness = 4.0 mm Scintillator – Polystyrene + 1.5%PT % POPOP Wave Length Shifting Fibers – Y11 Lucite prism for uniform light mixing 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 PID6 2-segment module design Separate light collection to 2-channel PMT V.Brekhovskikh, V.Rykalin 21 September 2006

ECAL PID7 All calorimeter Preshower Accepted electrons (84%) Rejected pions (93%) Beam measurements of 2-segment module V.Brekhovskikh, V.Rykalin 21 September 2006

ECAL PID8 Simulation model 1 module with 160 layers (Pb 0.7 mm + Sci 1.0 mm) Total radiation length: 20X longitudinal segments, each of 8 layers Various combinations of energies deposited in different segments allow to optimize longitudinal segmentation

ECAL PID9 E det vs Segment number: 5 GeV PhotonsHadrons

ECAL PID10 E det vs Segment number : 10 GeV PhotonsHadrons

ECAL PID11 E det vs Segment number : 15 GeV PhotonsHadrons

ECAL PID12 Longitudinal profile: Photons 5 GeV10 GeV

ECAL PID13 Longitudinal profile: Hadrons 5 GeV10 GeV

ECAL PID14 Longitudinal profile: Muons 5 GeV10 GeV

ECAL PID15 E1/E2, 5 GeV (1X 0 +19X 0 )

ECAL PID16 E1/E2, 5 GeV (2X 0 +18X 0 )

ECAL PID17 E1/E2, 5 GeV (3X 0 +17X 0 )

ECAL PID18 E1/E2, 5 GeV (4X 0 +16X 0 )

ECAL PID19 Identification probabilities (1X 0 +19X 0 ) E 1 /E2 cut GeV  - GeV  - GeV  - S/B=3.5

ECAL PID20 Identification probabilities (2X 0 +18X 0 ) E 1 /E2 cut GeV  - GeV  - GeV  - S/B=3

ECAL PID21 Identification probabilities (3X 0 +17X 0 ) E 1 /E2 cut GeV  - GeV  - GeV  - S/B=2

ECAL PID22 Identification probabilities (4X 0 +16X 0 ) E 1 /E2 cut GeV  - GeV  - GeV  - S/B=1.5

ECAL PID23 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