BESIII MCRelease notes & planned development
Dengzy, Hem, Liuhm, Youzy, YuanyNov. 23, 2005
What to cover?
• Retrospect
• Release notes
• Performance
• Planned development
HEP Software FrameArchitecture and modules are now exp. dependent
SIM: Fluka, Gheisha, …, G3, G4REC: Cleo, Belle, BaBar
ANA: Paw, Aida, … RootArchitecture: Basf, Root, Cobra, Gaudi
e+ e-
detector
physics
data
reconstruction
analysis
generator
tracking
digitization
event
hit
digit
MC
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!
