1. Performance of MB4 CHAMBERS GIORGIA MILA Sez. di Torno

2. 9-11-05 Giorgia Mila Sez. di Torno 2 OVERVIEW Map of MB4 dead channels Map of MB4 dead channels Inefficient cells & track angular distributions Inefficient cells & track angular distributions –BTI + TRACO acceptance (new vs old configuration files) On-going works : On-going works : –Efficiency –Resolution

3. 9-11-05 Giorgia Mila Sez. di Torno 3 sector-stationTURINISRCOMMISSIONING CHAMBER_2_4--- SL1 L3 w75 SL1 L4 w30 SL1 L4 w76 SL1 L3 w75 SL1 L4 w30 SL1 L4 w76 CHAMBER_3_4 SL1 L1 w31 SL3 L2 w4------ CHAMBER_5_4--- SL3 L1 w46 CHAMBER_6_4--------- CHAMBER_8_4--------- CHAMBER_12_4--------- MB4 DEAD CELLS – WHEEL 2 These cells seem to have been repaired We have not found any information about it

4. 9-11-05 Giorgia Mila Sez. di Torno 4 MB4 DEAD CELLS – WHEEL 1 sector-stationTURINISRCOMMISSIONING CHAMBER_2_4SL1 L4 w4 SL1 L1 w8,76,94 SL1 L2 w83 SL1 L4 w4 SL1 L4 w23 CHAMBER_3_4--------- CHAMBER_6_4--------- There are 5 new dead cells. we could not check the pulse files (the commissioning pc is down)

5. 9-11-05 Giorgia Mila Sez. di Torno 5 Angular distribution OLD vs NEW BTI configuration HH+HL OLD HH+HL NEW The angular acceptance of the HH+HL trigger has improved (see the right side of the distribution) This angular distribution is the convolution of : cosmic angular distribution BTI+TRACO angular acceptance MB4 sector3

6. 9-11-05 Giorgia Mila Sez. di Torno 6 BTI+TRACO acceptance versus cosmic angular distribution ~35° Correlated triggers ~-35° from Muon TDR

7. 9-11-05 Giorgia Mila Sez. di Torno 7 The Regular pattern in the occupancy plots (often related to distorted TB) seems to be strongly reduced!! We are studing the angular dependence of this pattern Occupancy OLD vs NEW BTI configuration MB4 sector3 HH+HL OLD HH+HL NEW

8. 9-11-05 Giorgia Mila Sez. di Torno 8 Occupancy – OLD BTI configuration The pattern is present at all angles -60°<angle<-30° 30°<angle<60° -30°<angle<30°

9. 9-11-05 Giorgia Mila Sez. di Torno 9 Strong angular dependence Occupancy – NEW BTI configuration -60°<angle<-30° 30°<angle<60° -30°<angle<30°

10. 9-11-05 Giorgia Mila Sez. di Torno 10 The problem is still present with the new BTI configuration : the effect is asymmetric is the asymmetry related to the effect of the staggering between the SLs on the TRACO ? (2 cells staggering for MB4) what is the origin of the 4 cell pattern? NOTE : The effect is present also in MB3 data taken with HH+HL trigger configuration Open problems

11. 9-11-05 Giorgia Mila Sez. di Torno 11 -30°<angle<-30°angle>60° 30°<angle<60° Occupancy MB3 – NEW BTI configuration HH+HL

12. 9-11-05 Giorgia Mila Sez. di Torno 12 Under study (I) EFFICIENCY Efficiency computed from segment extrapolation: count also hits not associated to the segment Mean efficiency: 98.5% count only hits associated to the segment Mean efficiency: 97.5% We need to agree on details about the efficiency calculation

13. 9-11-05 Giorgia Mila Sez. di Torno 13 σ = 520 μm Calibration parameters to be optimized with : recipe for t 0 subtraction v drift calibration Under study (II) RESOLUTION distance from the wire (cm) V drift effect

14. 9-11-05 Giorgia Mila Sez. di Torno 14 Test of ORCA reconstruction code This is a good opportunity also to test the official reconstruction code (ORCA) on real data: plenty of features under investigation. Bug found in the Segment reconstruction problems in RecHit update after segment fit in phi SLs: offset in z coordinate of segment position -> fix available Design problem for ORCA digis the current implementation of digis fails if there are more than 8 digis in a cell -> need to apply a time window during digitization (important feedback for implementation in CMSSW) Problem in the RecHit caching (found by Philipp) -> still to be fixed but it has no effect on commissioning data