1. Daniele De Gruttola (TOF group – Salerno University and INFN ) 2009 cosmic rays data analysis 09/Dec/09 ALICE - TOF meeting - CERN

2. Muons selection with TOF analysis based on: time-of-flight of muons measured by TOF τ = t – t o expected time-of-flight assuming relativistic muons τ exp = L/ c TOF hits: tracking system not included run 79774 (Aug 2009): 2512944 events - no magnetic field 09/Dec/09 ALICE - TOF meeting - CERN see R. Preghenella's talk

3. Full-TOF trigger (back-to-back ± 1) 09/Dec/09 ALICE - TOF meeting - CERN simulated trigger: 1 hit in an upper sector and 1 hit in the selected opposite ones

4. muon selection: purity ~ 95% 09/Dec/09 ALICE - TOF meeting - CERN Muons selection using tof

5. 09/Dec/09 ALICE - TOF meeting - CERN

6. distance between the hit pads on the opposite sectors vs difference between the hit times 09/Dec/09 ALICE - TOF meeting - CERN correlation between the time-of-flight and the track length Muons selection using tof --

7. 09/Dec/09 ALICE - TOF meeting - CERN ALICE coordinates

8. 09/Dec/09 ALICE - TOF meeting - CERN after the muon tracks selection on tof – L/c, it's possible to see a peak in the range 105° <  < 140 ° (corresponding to ALICE Baby side) Angular distribution

9. 09/Dec/09 ALICE - TOF meeting - CERN peaks related to trigger logic small peaks around φ = 180° and φ = 350° correspond to quasi horizontal tracks  Angular distribution

10. vertical tracks muons coming from the ALICE main shaft 09/Dec/09 ALICE - TOF meeting - CERN Theta Phi distribution

11. 09/Dec/09 ALICE - TOF meeting - CERN TOF supermodule Main shaft to lower detectors in the cavern

12. the event display shows the larger flow of muons coming from the main shaft (display over 2000 events for the sake of clarity) run 79774: 494527 selected tracks over 2512944 events ~ 32 % tracks coming from the shaft, ~ 23 % from opposite side z 09/Dec/09 ALICE - TOF meeting - CERN Theta distribution

13. service shaft ALICE cavern main shaft main shaft ALICE cavern service shaft ALICE P2 map 09/Dec/09 ALICE - TOF meeting - CERN 23 m Tracks surface distribution

14. 09/Dec/09 ALICE - TOF meeting - CERN Full-TOF trigger (back-to-back ± 3) 1 hit in an upper sector and 1 hit in the selected opposite ones

15. muons coming from the ALICE main shaft 09/Dec/09 ALICE - TOF meeting - CERN Theta Phi distribution

16. 09/Dec/09 ALICE - TOF meeting - CERN Angular distribution

17. 09/Dec/09 ALICE - TOF meeting - CERN Angular distributions in the two configurations  distribution with peak corresponding to ALICE main shaft ? slightly asymmetric φ distribution

18. 09/Dec/09 ALICE - TOF meeting - CERN sectors with no central modules (PHOS holes) sectors with no central modules (“simulated” PHOS holes) PHOS holes are not the cause of the φ distribution asymmetry: Muon Trigger has seen an effect due to Jura (its position corresponds to tracks at 270° < φ < 360°) φ distribution asymmetry back-to-back ± 3 back-to-back ± 1

19. good muon selection using only TOF hits purity ~ 95% reconstructed angular distribution reproducing the real one next step: clusterization ready to be applied to the analysis 09/Dec/09 ALICE - TOF meeting - CERN Conclusions

20. More

21. 09/Dec/09 ALICE - TOF meeting - CERN Clusters: Δ time vs Δ tot clusters on opposite sectors 2-pad clusters