ROOT VMC in OPERA OPERA physics Software framework

ROOT VMC in OPERA • OPERA physics • Software framework • Op. Sim: VMC simulation package • Specificities, requirements and milestones ROOT VMC workshop - CERN - December 2004 Lionel Chaussard

OPERA physics: - « low » energy (~1 -20 Ge. V) - short (~microns) and long dist. (~meters) ~ 10 m 2 73 km nm nt Pb … to find the « kink » of the tau t more than 200 000 bricks… t ~ 10 cm 1 mm ~ 50 mm ROOT VMC workshop - CERN - December 2004 … photographic emulsions scanned by microscopes…

OPERA software framework: - developed on RH 7. 3/cern, validated on SLC 3 - a serie of CMT pakages compatible with last ROOT and last VMC versions - Op. Sim (VMC) is one of the algorithms-like packages ROOT I/O interface Transient data model (STL) Op. Negn Op. Sim ( VMC ) Op. Digit Op. Rec Op. Display Detector description ( ROOT ) ROOT VMC workshop - CERN - December 2004 CMT manager ( incl. ROOT ) / CVS repository Persistent data model ( ROOT )

Configuration Management Tool: - all OPERA packages are CMT configured (Ch. Arnault, J. E. Campagne, LAL Orsay) CMT interface to ROOT VMC (e. g. geant 3) package ROOTVMC set ROOTVMC_DIR ‘‘${SOMEWHERE}/vmc’’ include_dirs ${ROOTVMC_DIR}/geant 3 path_remove LD_LIBRARY_PATH ‘‘vmc’’ Path_append_ LD_LIBRARY_PATH Linux‘‘${ROOTVMC_DIR}/geant 3/lib/tgt_linux’’ used in Op. Sim package: (requirement file from Op. Sim/v*/cmt) package Op. Sim author Toto use Opera. Policy v* use ROOTVMC v* CMTI branches doc … Some (not so difficult) problems: - geant 3: vmc library has the same name as cernlib one (libgeant 321) - geant 4: vmc include files are put in several directories - fluka ? ? ? ROOT VMC workshop - CERN - December 2004

Simulation package Op. RData data model (TObjects put in TLists posted in TFolders of TTree) -------------Op. IO interface (Tree. Manager) Config. MC. C (ROOT macro) GEANT 3 CM TI M C Op. Sim (TVirtual. MCApplication) -------------Op. Sim. Data. Store Op. Sim. Stack Op. Sim. Geom CMTI CM TI GEANT 4 V Set Roo t. Ge ome try () FLUKA Op. Sim. Particle (TObject, extension of RParticle) Op. Geom detector description ( TGeo. Manager ) ROOT VMC workshop - CERN - December 2004 Sens. Det*** (TNamed)

Op. Geom detector description: - from the ROOT TGeo. Manager package - OPERA volumes are « simple » , try to avoid ‘‘MANY’’ flag - Op. Geom. root file, less than 120 k. B, more than 48 Millions nodes - use Set. Root. Geometry() in Op. Sim VMC application ROOT VMC workshop - CERN - December 2004

Config. MC. C: Configure datastore Configure geometry Configure simulator ROOT VMC workshop - CERN - December 2004

Config. MC. C: No specific difficulty Cool ROOT VMC workshop - CERN - December 2004 !

Config. MC. C: Use only global GEANT 4 libraries for the time being geant 4_vmc libraries ROOT VMC workshop - CERN - December 2004 g 4 config. in: Pb: not really clear how to implement user’s physics list…

Specificities: - It seems that everything works well with geant 3 vmc - Some « technical » difficulties to work with geant 4 vmc (geometry control, physics list) - News for FLUKA vmc ? (Help « may » be provided) - tau generated particule and charmed generated particles are OPERA specific: - set lifetime to infinite - set decay modes to none (stable particules) - track these in emulsion and stop tracking on demand nt t m p D D or t -Yet simulator induced particules should be tracked/decayed as usual… Easy to implement in the vmc application using TGeant 3: : Define. Particle, More difficult in the geant 4 vmc case ROOT VMC workshop - CERN - December 2004

Milestones : - 2004 production (running): - still using « old » Op. Root package à la Ali. Root - still using ROOT 3. * - still running on RH 7. 3 / cern - 2005 production (planned): - should be done with Op. Sim using geant 3 vmc and ROOT 4. * - should be done on SLC 3 - test Op. Sim with geant 4 vmc - looking forward to fluka vmc - 2006 production (data taking!) - should be done with Op. Sim using fluka vmc ROOT VMC workshop - CERN - December 2004