1 / 21

Daniele De Gruttola (TOF group – Salerno University and INFN )

2009 cosmic rays data analysis. Daniele De Gruttola (TOF group – Salerno University and INFN ). ALICE - TOF meeting - CERN. 09/Dec/09. Muons selection with TOF. analysis based on: time-of-flight of muons measured by TOF τ = t – t o expected time-of-flight assuming

uma-garza
Download Presentation

Daniele De Gruttola (TOF group – Salerno University and INFN )

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

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

  2. Muons selection with TOF analysis based on: • time-of-flight of muons measured by TOF τ = t – to • 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 see R. Preghenella's talk ALICE - TOF meeting - CERN 09/Dec/09

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

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

  5. Muons selection using tof ALICE - TOF meeting - CERN 09/Dec/09

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

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

  8. Angular distribution 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) ALICE - TOF meeting - CERN 09/Dec/09

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

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

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

  12. Theta distribution z • 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: 494527selected tracksover 2512944 events • ~ 32 % tracks coming from the shaft , ~ 23 % from opposite side ALICE - TOF meeting - CERN 09/Dec/09

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

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

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

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

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

  18. φdistribution asymmetry back-to-back ± 3 sectors with no central modules (PHOS holes) sectors with no central modules (“simulated” PHOS holes) back-to-back ± 1 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°) ALICE - TOF meeting - CERN 09/Dec/09

  19. Conclusions • 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 ALICE - TOF meeting - CERN 09/Dec/09

  20. More

  21. Clusters:Δtime vsΔ tot • clusters on opposite sectors • 2-pad clusters ALICE - TOF meeting - CERN 09/Dec/09

More Related