HLT/AliRoot integration C.Cheshkov, P.Hristov 2/06/2005 ALICE Offline Week

2/06/2005HLT/AliRoot integration (C.Cheshkov) 2  Goal: As much as possible common code between online and “offline” HLT reconstruction and analysis chains  “Offline” HLT reconstruction chain: Debugging and studies on trigger efficiency, data rate reduction and etc. during the MC production Replay of the HLT response during the reconstruction of real data – for debugging and studies for possible improvements/optimization

2/06/2005HLT/AliRoot integration (C.Cheshkov) 3 Outline  HLT reconstruction chain in AliRoot Cluster finder + Track follower Hough transform + ITS tracking  HLT ESD  MUON HLT code  Conclusions and Outlook

2/06/2005HLT/AliRoot integration (C.Cheshkov) 4 HLT reconstruction in AliRoot  Cluster finder + Track follower: As “local” reconstruction (inside AliHLTReconstructor) Tracks & clusters stored temporarily in external binary files dE/dx computed during filling of ESD Tracks stored as AliESDHLTTrack  To do: Track parameter covariance matrix Track prolongation into ITS Tracks  AliESDtrack

2/06/2005HLT/AliRoot integration (C.Cheshkov) 5

2/06/2005HLT/AliRoot integration (C.Cheshkov) 6 HLT reconstruction in AliRoot  TPC Hough Transform + ITS tracking: Use the output of “default” ITS clusterer + vertexer Hough and ITS code as AliTracker inside RunTracking method of AliReconstruction: AliL3TPCtracker & AliL3ITStracker Offline AliTracker AliL3HoughKalmanTrack

2/06/2005HLT/AliRoot integration (C.Cheshkov) 7 Hough transform tracks  Class AliL3HoughKalmanTrack (derives from offline Kalman filter AliTPCtrack): Track parameter errors are proportional to Hough parameter space bin size Proportionality coefficient derived from the obtained resolution Errors on Hough parameters  Kalman track covariance matrix For proper propagation into ITS the Hough transform vertex constraint is released by resetting to zero non-diagonal elements in the cov.matrix  Hough tracks  ESD  ITS  ESD (likewise the offline reconstruction)

2/06/2005HLT/AliRoot integration (C.Cheshkov) 8 TPC only (HT) ITS+TPC Fakes

2/06/2005HLT/AliRoot integration (C.Cheshkov) 9 HLT reconstruction in AliRoot (Summary)  Version inside AliReconstruction as virtual sub-detector: AliReconstruction rec; rec.SetRunLocalReconstrction(“HLT ITS”); rec.RunVertexFinder(kTrue); rec.RunTracking(“HLT”); rec.FillESD(“HLT”);  Version used for benchmarking: Steering class inside RAW package Reconstruction directly from raw data HT  ITS  ESD

2/06/2005HLT/AliRoot integration (C.Cheshkov) 10 HLT Event Summary Data  HLT ESD stored as “chinese” copy of the offline ESD  Same AliESDs.root file but a separate tree – “HLTesdTree”  All the off-line macros and utilities work almost “automatically” for HLT: Attention to the tracking flags – only TPCin & ITSin

2/06/2005HLT/AliRoot integration (C.Cheshkov) 11 MUON HLT code  The goal is to have MUON HLT as a part of HLT module inside AliRoot repository  The basic changes needed to integrate the core MUON HLT library are done. Not yet in CVS.  To do: Only pure reconstruction code to comply the AliRoot coding rules The rest (online code) stays like it is Incorporation into the AliRoot reconstruction chain

2/06/2005HLT/AliRoot integration (C.Cheshkov) 12 Conclusions and Outlook  Cl.finder + tr.follower: Organize as AliTracker Track cov.matrix Propagation to ITS Filling of the ESD  TPC Hough + ITS tracking: Incorporation is done Emulation of HT FPGA?  MUON HLT code is almost there  TRD trigger emulation?  TRD tracking and PID  Usage of Root/AliRoot libs in the online code?  ESD in the online code?