Monthly video-conference, 18/12/2003 P.Hristov1 Preparation for physics data challenge'04 P.Hristov Alice monthly off-line video-conference December 18, 2003 CERN

Monthly video-conference, 18/12/2003 P.Hristov1 Goals ■ Determine readiness of the off-line framework for data processing ■ Validate the distributed computing model ■ PDC'04: 10%fraction of the final capacity: ■ Complete chain used for trigger studies ■ Prototype of the analysis tools ■ Comparison with parameterised MC ■ Simulated raw data ■ Physics: hard probes (jets, heavy flavours)

Monthly video-conference, 18/12/2003 P.Hristov1 PDC'04 strategy ■ Distributed simulation and production of summable digits ■ Data transfer back to CERN ■ Distributed merging, digitization, clusterization, reconstruction, PID, production of ESD ■ Distributed analysis

Monthly video-conference, 18/12/2003 P.Hristov1 Root & Geant3 ■ Root v released (17/12/2003) ■ Several improvements in the storage of trees (very important for pp production) ■ Seems to work with the HEAD of AliRoot ■ PRM distribution for LCG exists ■ Geant3 ■ Version v0-5 tagged ■ Possibility to use the geometrical modeler and/or Geant3 native transport ■ No RPM yet

Monthly video-conference, 18/12/2003 P.Hristov1 Generation ■ 10^5 underlaying Pb-Pb HIJING events ■ Centrality classes corresponding to equal cross section: 0-5,5-8.6, , , , fm ■ 10^7 p-p PYTHIA events (at the end of the PDC, waiting for a tuned version of PYTHIA) ■ Signal events (PYTHIA): ~50 for each underlaying event and for each physics case ■ Jets: energy bins from 10GeV with 20% increase ■ Open charm: D0 ■ Decays containing electrons (J/psi, Y, etc.)

Monthly video-conference, 18/12/2003 P.Hristov1 Generation II ■ HIJING quenching vs no quenching ■ A problem in the phi distribution of particles with quenched HIJING investigated and solved. ■ Proposal: use in the beginning simulation without quenching

Monthly video-conference, 18/12/2003 P.Hristov1 Geometrical description ■ New coordinate system: OK ■ Most of detectors are ready for PDC'04 ■ Still overlaps in ITS ■ TOF geometry (holes only for PHOS): ready, some changes in the FRAME needed before the commit ■ V0, FMD, START are about to commit the changes

Monthly video-conference, 18/12/2003 P.Hristov1 Simulation ■ Magnetic field: the barrel field is constant, the Bz component is interpolated between the barrel and dipole regions. ■ Vertex for the signal events: taken from the underlaying event, new class implemented

Monthly video-conference, 18/12/2003 P.Hristov1 Detector response ■ Exists for all detectors ■ Comparison with beam data: MUON, PHOS, TPC, TRD ■ Ongoing work ■ MUON ■ PMD ■ TRD ■ Hits: we do not keep except for the detectors without summable digits

Monthly video-conference, 18/12/2003 P.Hristov1 Summable digits ■ Exist for all detectors which will use event merging ■ No problems reported ■ Event merging: works with AliSimulation class for all the barrel detectors. The rest is available as macros

Monthly video-conference, 18/12/2003 P.Hristov1 Digitization ■ OK for all the detectors ■ Event merging strategy: 1 HIJING event is combined 50 times with simulated hard probes (jets, heavy flavors, ets.) ■ We do not store any intermediate files

Monthly video-conference, 18/12/2003 P.Hristov1 Reconstruction ■ OK for all the detectors. ■ Kalman tracking chains: ■ TPC->ITS->TPC->TRD->TOF: OK ■ TRD->TPC-->ITS ■ The results are stored in ESD ■ V0 and cascade reconstruction: OK, included in ESD ■ Primary vertex: OK, but not yet in ESD

Monthly video-conference, 18/12/2003 P.Hristov1 Particle identification ■ Framework for combined PID ■ ITS, TPC, TRD, TOF included in ESD ■ Standalone PHOS, EMCAL, and RICH PID

Monthly video-conference, 18/12/2003 P.Hristov1 ESD ■ A lot of improvements, the barrel detectors are OK ■ Still incomplete...

Monthly video-conference, 18/12/2003 P.Hristov1 Distributed computing ■ AliEn is ready (?) for the mass production ■ Additional work is needed to install the production version on the remote sites ■ A lot of progress in the field of distributed analysis ■ The users have to learn how to use all these new tools

Monthly video-conference, 18/12/2003 P.Hristov1 Check list ■

Monthly video-conference, 18/12/2003 P.Hristov1 Release issues ■ Release: in January ■ Improvement of the code performance ■ Run time errors (valgrind, Root): OK ■ Profiling ■ Optimization ■ Algorithms

Monthly video-conference, 18/12/2003 P.Hristov1 Plans ■ Release ■ Preproduction: 12/01/2004 – 31/01/2004 ■ Production of underlaying events: ■ Waiting for LCG-2 in February ■ Start with AliEn alone in case of LCG-2 problems ■ Production of signal events -> ESD ■ Analysis ■ Proton-proton

Monthly video-conference, 18/12/2003 P.Hristov1 Merry Christmas and Happy New Year!