besiii simulation status z.y. deng m. he h.m. liu y.j. mao z.y. you y.yuan bes annual meeting june...
TRANSCRIPT
BESIII Simulation Status
Z.Y. Deng M. He H.M. Liu Y.J. Mao Z.Y. You Y.Yuan
BES Annual MeetingJune 1, 2005
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Outline
Introduction
Current status
Performance
Future work
Summary
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GeometryGeant4
Tracking
DetectorDigitization
Response
Hitobjects
EventGENBESGenerator
HepEvtformat
Raw dataMC truth
BOOST Project (BESIII Object Oriented Simulation Tool)
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BOOST Project (BESIII Object Oriented Simulation Tool)
Components Generator Particles and physics processes Magnetic field Material MC truth Data I/O User interface Geometry Hits recording Digitization
sub-detector parts
common parts
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boost/ bes/ common part src/ source c++ codes include/ header files
gen/ … event generators phy/ … physics processes tru/ … MC truth gmk/ … common makefiles mac/ … common card files dat/ … geometry data files exe/ … main program for execution doc/ … documentations mdc/ … main drift chamber tof/ … time of fight emc/ … electromagnetic calorimeter muc/ … muon chamber
BOOST code structure
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BOOST Project (BESIII Object Oriented Simulation Tool)
Developers Liu Huaimin: common parts Yuan Ye: MDC Deng Ziyan: TOF & common parts Fu Chengdong/He Miao: EMC Peking University: MUC & xml geometry
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BOOST Project (BESIII Object Oriented Simulation Tool)
Phase 1: Framework prototype, simple geometry with hit Finished, BOOST prototype realized in May,2003
Phase 2: Detailed detector with simple digitization Finished, now digits and MC truth output can be used for
reconstruction
Phase 3: Detailed digitization, data/MC comparisons In progress, need information from beam test and data.
A long-term work!
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Geant4 and BOOST releasesGeant4
Release 6.1 March, 2004 Release 6.2 June, 2004 Release 7.0 December, 2004 Patch of 7.0 February, 2005
BOOST (mantained by cvs) ‘boost-1-0’ (March, 2004) -----Geant4.6.1 ‘boost-1-1’ (June, 2004) -----Geant4.6.2 …… ‘boost-2-0’ (February, 2005) ----Geant4.7.0 ‘boost-2-1’ (May, 2005) ----- Geant4.7.0+p01
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BOOST Current Statusgeometry
Detailed BESIII geometry is constructed in BOOST
Geometry added since last annual meeting Accurate stereo cells in MDC New End-cap EMC SCM (Super-Conducting Magnet )
BESIII Geometry in XML format Geometry in BOOST now can also be constructed with XML Simulation, reconstruction, event display will share the same BES
III geometry See detailed information in Mao Yajun’s report
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BOOST Current Status MDC stereo cell
Accurate description New class (J4TwistedTubs) introduced all stereo wire cells are constructed
Display for checking Twisted tube can’t be displayed directly hit positions in stereo cell used 3D scatter plot with ROOT package
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BOOST Current Status end-cap EMC geometry
Quadrangular crystal Irregular boxoid Can’t be described by existing classe
s in Geant4 releases New class (G4IrregBox) introduced
Pentangular crystal Divided into 2 boxoids 2 boxoids share the same copy numb
er
quadrangular crystal
pentangular crystal
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BOOST Current Status end-cap EMC geometry
construct all crystals in one sector
Place other sectors through rotation and reflection
Rotate east end-cap to place west end-cap
end-cap EMC
sector
rotation
reflection
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BOOST Current Statusgeometry
From boost-2-1
barrel: MDC, TOF, EMC, SCM, MUC end-cap: TOF, EMC, MUC
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BOOST Current Statusgenerator
genbes: (BESII generator system) Generate events in an ASCII file which supports HEPEVT inter
face with Geant4
The same user interface as BESII• genbes.cards , genbes.user
All BESII generators can be used in BOOST
tester: (single-particle generator for debugging) Shoot particles of given type to a given direction with given kinetic energy Users can randomize above quantities
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BOOST Current Statusgenerator: howl
J/ψKs Ks π+π-π+π-
Hits in MDC
Hits in barrel TOF(no threshold cut)
Hits in end-cap TOF
Hits in end-cap MUC
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BOOST Current Statusgenerator: rhopi
J/ψρπ π+π-
Hits in barrel MUC(π- punch through)
Shower in EMC
gamma
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BOOST Current Statusprocesses & magnetic field & material
Physics processes BesPhysicsList constructed with Geant4 classes Many hadronic models installed, LHEP, LHEP-GN, Q
GSP-GN, …… More research on them needed to choose suitable
ones for BESIII physicsMagnetic field
1 Tesla uniform magnetic field defined inside SCMMaterial
All materials needed in BOOST defined in XML
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BOOST Current Statushits and digitization
Hits recording Finished last year
digitization MDC
• Drift distance-> drift time• dE/dx• Wire resolution added• Simple background added
TOF• Detailed digitization• Light emission & light propagation• PMT response & threshold discrimin
ation
EMC • waveform added• Simulate main amplifier output• Provide risetime to eliminate no
ise• No noise, so not used now
MUC• Digit information added
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BOOST Current StatusMC truth
Purpose To provide truth information for
reconstruction debugging Similar to MCMADE in BESII
What to save True state of the particles and their
association with detector response• Particle
• particles from generator • uninterrupted decayed daughters
• Detector response• hits in sub-detectors associated with particles
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BOOST Current StatusMC truth
Track and vertex (associated with particle)
Track • PDGcode• charge• original vertex• terminal vertex• four-momentum• decayed daughters
Vertex• parent track• position • time
truth hits (associated with track)
Considering demand of each reconstruction developer
MDC• Hit history
TOF• First-hit
EMC• Total energy loss
MUC• Hit history
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BOOST Current StatusData I/O
Ascii data I/O It’s temporary, but useful in software (SIM + REC) development
Ascii data format fixed for the moment
MC truth (TRUTH) & Raw data (DIGI) included in one file
• EVHEAD• TRACKTRUTH, VERTEXTRUTH• MDCTRUTH, MDCDIGI• TOFTRUTH, TOFDIGI• EMCTRUTH, EMCDIGI• MUCTRUTH, MUCDIGI
Users can turn on/off TRUTH and DIGI part of each sub-detector in run cards
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BOOST Current StatusUser interface
Friendly to both users and developers source ~dengzy/.boostenv cvs co boost edit boost.cards & boost.user more controls in run cards
Run background/terminal/interactive/PBS job freely boost -b/-t/-i/-q use ‘boost –h’ for detail
Reconstruction developers can generate needed data files themselves
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BOOST PerformanceSpeed
From LHC experience G4 direct comparison with G3 G4 is slower (1.5~2) than G3 G4 tracking particle to 0 energy
Compared with SIMBES SIMBES (G3/BESII), BOOST (G4/BESIII)
How to compare Similar cuts
• CUTE CUTM (10KeV), range cuts (1mm) Same platform (Besfarm7) Physics events used (dimuon, rhopi, bhabha)
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BOOST PerformanceSpeed
CPU time (s) for one eventBesfarm7 (PIII/933)
Event SIMBES BOOST
ee -> uu 0.122 0.189
J/ψ->ρπ 0.471 0.763
ee -> ee 0.736 1.224
BOOST 1.5 times slower than SIMBES
More to do about speed improvement Threshold cut in digitization Speed of hadronic models to be compared
Stable (no crash for 100,000 events)
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BOOST PerformanceMDC
P distribution (1GeV/c e-)
σp =6.1MeV
P distribution (1GeV/c mu-)
σ p=5.8MeV
Reconstruction result using BOOST data sample
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1GeV/c e- vertical incidence
total energy loss in one scintillator (5cm width)
BOOST PerformanceTOF
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BOOST PerformanceTOF
e- 1GeV/c Z=0 : forward TDC resolution = 121ps backward TDC resolution = 122ps
T : 1/sqrt(Q)
time-walkforward
backward
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BOOST PerformanceTOF
e
μπ
kp
Randomly generate particles: e-, mu-, pi-, kaon-, protonMomentum: uniform between 0-1.6 GeV/cOnly intrinsic time resolution
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BOOST PerformanceEMC
total energy loss of pi- e-
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BOOST PerformanceMUC
Probability of single particle(μπ) entering MUC
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BOOST Integration to BOSSframework
Different developing environment BOOST
• On besfarm• Configured with gmak
e• Based on GEANT4
BOSS• On koala• Configured with CMT• Based on GAUDI
Integration Status BOOSTAlg algorithm/packages c
reated in BOSS
Key functions of BOOST realized in BOSS
Interface of saving data to TDS is ok
Codes imported into cvs
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Future Work
Move developing environment from besfarm to lxplus
Magnetic field mappingPhysics validation, optimizationData I/O
Objectivity? Raw data in online format, MC-Truth format?
Background, noise?Detailed detector response
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Summary
Detailed BESIII detector is built in BOOSTAll BESII generators can be used in BOOSTRaw data/MC-truth data are successfully
used in reconstructionFriendly user interfaceBOOST integrated into BOSSPrototype of TOF detailed digitization is
realizedMore to do about detector response !
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Thank you !