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!