12th CBM Collaboration MeetingOctober 13-18, 2008, JINR, Dubna

A. Zinchenko1

(L.Naumann2, D.Peshekhonov1, V.Peshekhonov1) 1VBLHEP, JINR, Dubna

2Forschungszentrum Dresden-Rossendorf, FZD

Feasibility study of the straw tube detector option for some MUCH

stations

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1. MC

2. Reconstruction

3. Some performance numbers

4. Summary and outlook

Outline

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Tube diameters: 4, 4, 4, 4 mm; σdrift = 0.2 mm6 layers per station arranged in 3 doublets: Y, U (+10o), V(-10o)

Geometry

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Straw tube occupancy for Au-Au @ 25 GeV

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Straw tube occupancy for Au-Au @ 25 GeV

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Makes use of L1 Kalman Filter framework (CbmL1SttTrackFinder)

Starts from STS tracks

Tracking strategy: extrapolate track to STT plane and select hits around track with χ2 < 20 (100)

Track accepted if contains hits from all STT doublets

Track reconstruction

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Reference tracks: muon tracks from J/ψ found in STS and passing through all layers of STT (producing STT MC points with given MC track ID)

Tracking efficiency

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J/ψ to dimuon @ 25 GeV w/out background

1165 / 1185 = 98.3 %

1166 / 1194 = 97.7 %

1165 / 1185 = 98.3 %

1166 / 1194 = 97.7 %

100

1106 / 1185 = 93.3 %

1113 / 1194 = 93.2 %

1113 / 1185 = 93.9 %

1118 / 1194 = 93.6 %

20

4 stations (hit merging)

3 stations (hit merging)

4 stations3 stationsχ2-cut

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J/ψ to dimuon + central Au-Au @ 25 GeV

1157 / 1183 = 97.8 %

1162 / 1195 = 97.2 %

1160 / 1183 = 98.1 %

1162 / 1195 = 97.2 %

100

1063 / 1183 = 89.9 %

1110 / 1195 = 92.9 %

1107 / 1183 = 93.6 %

1120 / 1195 = 93.7 %

20

4 stations (hit merging)

3 stations (hit merging)

4 stations3 stationsχ2-cut

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• STT occupancy inside MUCH is below 10% in stations 4-6 for central Au-Au for 25 GeV/c

• first track reconstruction results from STS seeds (without MUCH tracking) look promising both for 3 and 4 STT stations

Summary

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• realistic STT geometry

• STT software

• performance with MUCH tracks

Outlook