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ALICE TOF FESTIVAL Offline tools and GRID scenario for the ALICE TOF detector A. De Caro (University of Salerno and INFN) CERN – Bdg.29, October 20 th 2008

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ALICE TOF Offline Group activities ALICE software, AliROOT: the detector geometry ( materials and geometrical distributions ); the real MRPC features ( t and time-over-threshold ); the cluster finder; the reconstruction algorithm ( matching ); the particle identification ( PID ); the alignment procedure; the calibration ( time slewing corrections and cable delays ); the optimization of the online - offline connections ( databases ); event display. A lot has been already done… …but still a lot remains to do. Nevertheless we are in good shape. A. De Caro 2 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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Outline TOF geometry: simulation details TOF MRPCs: simulation of the test beam results TOF clustering: new algorithm implementation TOF particle identification First cosmic through tracking detectors matched with TOF detector First alignment studies Some of the ALICE TOF Offline Group successes A. De Caro 3 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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Materials, shapes and their geometrical distributions in the ALICE reference frame

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April 24 th 2008: all 18 TOF supermodules installed SM0 SM1 SM2 SM3 SM4 SM5 SM6 SM7 SM8 SM9 SM17 A. De Caro 5 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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SM0 SM1 SM2 SM3 SM4 SM5 SM6 SM7 SM8 SM9 SM10 SM11 SM12 SM13 SM14 SM15 SM16 SM17 TOF SMs as described in the AliROOT framework A. De Caro 6 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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TOF SM: services detail realsimulation A. De Caro 7ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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Finger to cool NINO ASIC real simulation TOF SM: front-end electronics detail A. De Caro 8 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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Description of the real MRPC features: detection efficiency (time resolution and time-over-threshold) as a function of the hit pad position

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TOF MRPC strip: hit and activated pads Pads possibly activated by electrical induction effects Pad hit by a particle X Z Y A. De Caro 10 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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TOF MRPC strip: detection efficiency CERN-Bdg.29, October 20th 2008ALICE TOF FESTIVAL A. De Caro 11 3 15 4 26

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TOF MRPC strip: detection efficiency CERN-Bdg.29, October 20th 2008ALICE TOF FESTIVAL A. De Caro 12 3 15 4 26

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TOF MRPC strip: detection efficiency CERN-Bdg.29, October 20th 2008ALICE TOF FESTIVAL A. De Caro 13 3 15 4 26

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TOF MRPC strip: detection efficiency CERN-Bdg.29, October 20th 2008ALICE TOF FESTIVAL A. De Caro 14 3 15 4 26

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TOF MRPC strip: detection efficiency CERN-Bdg.29, October 20th 2008ALICE TOF FESTIVAL A. De Caro 15 3 15 4 26

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TOF MRPC strip: detection efficiency CERN-Bdg.29, October 20th 2008ALICE TOF FESTIVAL A. De Caro 16 3 15 4 26

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TOF MRPC strip: detection efficiency 3 15 4 26 A. De Caro 17 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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Standard clustering algorithm: one cluster per each fired pad. New clustering algorithm: one cluster per each set of neighbouring fired pads with comparable time measurements (according to the time resolution). Cluster time: currently, the time weighted average (per tot); with calibration parameters, better estimation (NIM A532, 611-621, 2004). Similar remarks for the cluster position.

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con segnale senza segnale TOF multi hit associated to the same particle fired not fired A. De Caro 19 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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Comparison between the two clustering algorithms In blue: standard TOF cluster In red: new TOF cluster In green: TOF pad interested by signal TOF strips as tracking detectors In yellow: standard TOF cluster fit In violet: new TOF cluster fit D. De Gruttola, Phd thesis, Salerno May 9th 2008 TOF strip in test A. De Caro 20 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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Detail on the pad interested by signal, 7 th strip, the one in test. The violet line crosses the strip in test while the yellow one does not. The chosen order parameter is the distance between the impact point of the reconstructed track to the hit pad centre. This order parameter is minimum in case of new TOF cluster fit. In blue: standard TOF cluster In red: new TOF cluster In green: TOF pad interested by signal In yellow: standard TOF cluster fit In violet: new TOF cluster fit Comparison between the two clustering algorithms D. De Gruttola, Phd thesis, Salerno May 9th 2008 A. De Caro 21 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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ALICE TOF detector performances: reconstructed mass vs momentum and PID efficiency and contamination in p-p and central Pb-Pb collisions

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Mass vs momentum (PPR 2 nd vol.) A. De Caro 23 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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TOF PID efficiency and contamination (PPR 2 nd vol.) A. De Caro 24ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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Some results obtained with the analysis of the data taken during the cosmic runs (12/07-09/08) with/without L3 magnetic field. Good chance to test the code with real data.

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Cosmic muon reconstructed in ALICE detector (B=0 T) t1 t2 t1

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Prospective view A. De Caro 27 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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t1 t2 t1

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A. De Caro 29 - Prospective view A. De Caro 29 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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To check the functionalities of the alignment algorithm with real events

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Distance-approach ( -z view) First alignment step for the TOF detector: along the beam direction, i.e. the z axis. Distance-approach: the distance between the impact point of the reconstructed track on the TOF strip and the closer TOF cluster centre (schematically shown here). The z component of the distance-approach is the parameter used to align TOF SMs along z axis. =371 cm Reconstructed track A. De Caro 31ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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Distance-approach distributions (B=0 T) A. De Caro 32 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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Distance-approach distributions (B=0 T): aligned geometry A. De Caro 33 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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Distance-approach vs strip per TOF SM (B=0 T) A. De Caro 34 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008 TPC: field cage internal wall

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Distance-approach vs strip per TOF SM (B=0.5 T) A. De Caro 35 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008 TPC: field cage internal wall Caused by a not corrected calibration for the drift velocity (TPC people confirmed).

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Several successes obtained by the TOF Offline Group. Some of them publicly acknowledged by the ALICE Offline Group (green light for the TOF detector)

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F.Carminati @ May 2007 Technical Board http://indico.cern.ch/materialDisplay.py?contribId=14&materialId=slides&confId=7361 Written code / code to be written [%] T O F Average 81.5% A. De Caro 37 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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Shuttle algorithm: online offline Responsible: C. Zampolli http://aliceinfo.cern.ch/Offline/Activities/Shuttle.html A. De Caro 38 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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Raw data implementation status http://aliceinfo.cern.ch/Offline/Activities/Raw-Data.html TOF A. De Caro 39 ALICE TOF FESTIVALCERN-Bdg.29, October 20th 2008

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ALICE TOF FESTIVAL A. De Caro 40

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