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Real data reconstruction A. De Caro (University and INFN of Salerno) CERN Building 29, December 9th, 2009ALICE TOF General meeting.

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Presentation on theme: "Real data reconstruction A. De Caro (University and INFN of Salerno) CERN Building 29, December 9th, 2009ALICE TOF General meeting."— Presentation transcript:

1 Real data reconstruction A. De Caro (University and INFN of Salerno) CERN Building 29, December 9th, 2009ALICE TOF General meeting

2 Data acquisition: preparation  Definition status of readout channels (offline condition database):  on/off: Front-End Electronics database, coming from Detector Control System  dead/alive (pulser runs)  noisy/not-noisy (noise runs)  Definition of reconstruction parameters (offline condition database) –from Montecarlo studies-:  matching window,  2 track cut, etc.  Definition of alignment parameters (alignment database)  Definition of calibration parameters (calibration database) CERN Building 29, December 9th, 2009A. De Caro 2ALICE TOF General meeting

3 When a run acquisition ends…  In case of physics runs:  a fast procedure calculates the first raw calibration parameters  For cosmic runs and first collisions, these raw parameters are the ones obtained with cosmic data calibration procedure (see R.Preghenella talk).  For future collisions, the raw calibration parameters will be the delays with respect to the expected time for primary pions at  =1 (see C.Zampolli talk).  Then, these raw calibration parameters are written to the calibration database.  In case of noise/pulser runs:  The status of all TOF channels is written in the offline condition database. CERN Building 29, December 9th, 2009A. De Caro 3ALICE TOF General meeting

4 Run reconstruction (1) It is a public and global work. It runs on the GRID (see F.Noferini talk).  Raw data decoding  Each detector has developed its own code decoding, tested on the Montecarlo data and then tuned on the cosmic data.  At this point the TOF channel status is controlled in the offline condition database.  Tracking  The ALICE tracking detectors (TPC -main-, ITS and TRD) collect together their own clusters to form tracks CERN Building 29, December 9th, 2009A. De Caro 4ALICE TOF General meeting

5 Run reconstruction (2)  Track matching with the other detectors  Each external barrel detector -first of all TOF, then HMPID, PHOS and EMCal- has developed and provided its own code of detector- track matching.  At this point the calibration and the alignment parameters are taken into account. The whole experiment code is public and available to all. The TOF code as seen offline has just been checked by the ALICE Detector Performance Working Group Coordinator on p-p events @ 900 GeV: “All this is getting more and more interesting !” CERN Building 29, December 9th, 2009A. De Caro 5ALICE TOF General meeting

6 What did I do? And what am I doing?  I checked/debugged:  the proper functioning of the noisy/not-noisy TOF channel definition;  that the reconstruction parameters used to reconstruct real events (i.e. cosmic and first p-p collision runs) were the right ones;  the TOF raw data decoding.  Chiara and I are checking the fast online TOF calibration procedure.  I am checking the TOF-track matching algorithm.  For my studies as well as for first data analysis, the event display is a very useful analysis tool. I implemented the TOF event display code and I am still developing and updating it. CERN Building 29, December 9th, 2009A. De Caro 6ALICE TOF General meeting

7 One of cosmic  s triggered and seen by ALICE TOF detector CERN Building 29, December 9th, 2009A. De Caro 7ALICE TOF General meeting

8 September 25 th, 2009: injection test TOF occupancy ~50% CERN Building 29, December 9th, 2009A. De Caro 8ALICE TOF General meeting

9 November 21 st, 2009: beam-gas collision seen by ALICE TOF detector  z V is the interaction vertex distance from the ALICE reference system centre. It has been estimated to be ~6.2 m (only via TOF time measurements) zVzV CERN Building 29, December 9th, 2009A. De Caro 9ALICE TOF General meeting

10 November 21 st, 2009: beam-gas collision seen by ALICE TOF detector CERN Building 29, December 9th, 2009A. De Caro 10ALICE TOF General meeting

11 November 21 st, 2009: beam-gas collision seen by ALICE TOF detector CERN Building 29, December 9th, 2009A. De Caro 11ALICE TOF General meeting

12 December 6 th, 2009: first p-p collisions seen by ALICE TOF detector also CERN Building 29, December 9th, 2009A. De Caro 12ALICE TOF General meeting

13 December 6 th, 2009: first p-p collisions seen by ALICE TOF detector also CERN Building 29, December 9th, 2009A. De Caro 13ALICE TOF General meeting


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