BESIII MC Release notes & planned development Dengzy, Hem, Liuhm, Youzy, Yuany Nov. 23, 2005

What to cover? Retrospect Release notes Performance Planned development

HEP Software Frame Architecture and modules are now exp. dependent SIM: Fluka, Gheisha, …, G3, G4 REC: Cleo, Belle, BaBar ANA: Paw, Aida, … Root Architecture: Basf, Root, Cobra, Gaudi

e+e- detector physics data reconstruction analysis generator tracking digitization event hit digit MC design efficiency background track signal

BOOST Project BESIII Object Oriented Simulation Tool (proposal: August, 2002) BES MC Software Evolution BESI BESII BESIII SOBER SIMBES BOOST EGS G3 G4 1980s 1990s 2000s

BOOST: 3 phases Phase 1: Framework prototype, simple geometry with hit Finished in May 2003 Phase 2: Detailed BESIII detector with simple digitization Finished in May 2004, digit outputs can be used to tune the reconstruction program Phase 3: Detailed digitization, data/MC comparisons Need information from beam test and data. We are here!

BESIII offline software Simulation: mimic experiment, as close as real Reconstruction: retrieve physics quantities from data Calibration: make possible corrections to data Framework: provide common services to all modules AnalysisTool: make physics analysis easier

Release notes (sub-detectors) MDC Geometry: small overlap detected, and corrected, dead-loop in tracking eliminated new MDC geometry passed test Digitization: wire resolution using two gaussians momentum resolution turns a bit smaller MCtruth: add more information, like LR ambiguity

Release notes (sub-detectors) TOF Geometry: new barrel double-layer structure, scintillator wrapper added end-cap TOF extruding problem solved Digitization: full detector response as default

Release notes (sub-detectors) EMC Geometry: support structure (cables) added Digitization: electronic noise added MUC Geometry : using new alignment data

Release notes (common parts) Magnetic field Geant4 default parameters (step size, intersection) reused Momentum resolutions are ok for leptons and hadrons Physics interaction BesPhysicsList: not stable for hadrons Geant4 recommended packages are used

Release notes (common parts) GDML (XML) Rewrite MUC & TOF, can be shared by REC MDC & EMC remain unchanged Use code to build BESIII detector in this release

Performance (on lxplus) Simulation speed Depends on event type Using Tester, Bhabha, Dimuon, Hadronic, inclusive J/Psi events Geant4.7.0 (BOSS), Geant4.7.1 (BOOST) CPU time, roughly, 1 second for one event No crash/dead-loop for about 50K events

Performance (on lxplus) Memory consumption Roughly 80M memory needed About 4M memory leak for 10K events Memory leak depends on particle type, mainly comes from G4 interaction packages

Performance (on lxplus) Physics quantities Key physics quantities/parameters checked momentum/time/energy resolutions, reconstruction efficiencies, … Satisfactory & understandable So far so good

Planned development Geometry – 12/2005 New EMC & MDC description Magnetic field – 02/2006 3D field map in the whole detector propagation parameters optimization Interaction packages – 12/2005 Different hadronic packages Standard and Low EM packages

Planned development Background simulation – 06/2006? Bianjg is working on it Trigger simulation – 12/2006? Caogf will work on it Move to new G4 and GDML – 01/2006? Gean4.7.1  Geant4.7.2 (12/2005) GDML1.0  GDML2.3.0 (08/2005)

Planned development Real detector simulation – 10/2006? Rethink about BESII scheme Using Calibration constants? Wire resolution/ efficiency, dead/hot channels, … MCtruth binary output – 03/2006? Needed to save space Detector response – 11/2005 … Long-term work

If you have problem … Judge before shouting Correct environment? Correct cards? Am I right? Report to developers Crash? Dead-loop? Abnormity? Discuss with experts Hard-to-understand resluts

What is MC? doing experiment in computer 纸上谈兵 运筹帷幄决胜千里

Thank you!