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Particle Identification in CBM. Geometry and acceptance at 25 AGeV Hadron i dentification - TOF p erformance - Matching to the Silicon Tracker Summary. K. Wisniewski, FOPI Coll., Uniwersytet Warszawski, Universität Heidelberg. (New) CBM Geometry.
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Particle Identification in CBM • Geometry and acceptance at 25 AGeV • Hadron identification - TOF performance - Matching to the Silicon Tracker • Summary K. Wisniewski, FOPI Coll., Uniwersytet Warszawski, Universität Heidelberg
(New) CBM Geometry Electrons - RICH, TRD Hadrons - Time of Flight (RPC) • Silicon tracker • - p determination • sec. vertex Geometrical acceptance : lab 5 – 30o
Phase-space Distribution at 25 AGeV • Hadron identification up to 5 GeV/c • K/ separation up to 5 GeV/c • large distance from the target • large scale (high cost) • High-rate capability (up to 20 kHz/cm2) • Good time resolution
Hadron Identification by TOF • TOF wall located 15 m from target • K,yields from UrQMD, Au+Au,25AGeV • S/B depends on TOF resolution • Required S/B for K: 10 • K/ separation with 80ps device: up to 4 GeV/c
D0 Efficiency • Good mid-rapidity coverage • D0 detectability as low as 10%(pmax=4 GeV/c) • Factor 3 better with pmax=6 GeV/c As good as poss. time resolution needed
ALICE Pad-Anode FOPI Strip-Anode Timing Multi-gap Resistive Plate Chambers • Very good time resolution • Negligible tails • High efficiency • High granurality • Low cost • High-rate capability is a • problem (2 kHz/cm2) • A4 glass • geometry optimisation • Ageing needs to be tested
Matching to the Silicon Tracker • Matching distorted due to mult. scattering • Accuracy of the extrapolation depends on distance • Extrapolation over 5 m. of RICH • Perfect position resolution assumed
Efficiency and Misidentification • Hit-search radius 2x,y (86% efficiency): 20.18cm (1 GeV/c) 20.09cm (2 GeV/c) • Biggest confusion close to the target (Silicon) and at small angles (5o) • Double hit probability at 5o: 15% (1 GeV/c) 4% (2 GeV/c) • Misidentification probability (15%)/2 (with no background particles)
Summary • PID needs a good tracking system(avoid large gaps) • optimisation of RICH (splitted into two parts) • tracking on the way to TOF (additional TRD stations) • TOF-based PID limited to 4-6 GeV/c (for K/ separation) • Good coverage of the D0 phase-space distribution (mid-rapidity) • D0efficiency 10-30% (depending on pmax) go for as good as possible TOF resolution use other technique for the K/separation at high p (RICH?)
Monolithic Activ Pixel Sensors (MAPS) • Excelent hit resolution (3 m) • Small thickness (20 m) • Not radiation-hard • Slow readout