This is an old revision of the document!
It can be very useful to let Gauss write out MCParticles in the Generation directly (without the detector simulation), which then can be analysed. This can be achieved the following way (write this at the end of your version of Gauss-Job.py):
gtos = GenerationToSimulation() gtos.SkipGeant = True gs = GaudiSequencer("GenMonitor") MCTruthStream = OutputStream("MCTruthStream") MCTruthStream.ItemList += [ "/Event/Gen#1", "/Event/Gen/HepMCEvents#1", "/Event/MC#1", "/Event/MC/Header#1", "/Event/MC/Particles#1", "/Event/MC/Vertices#1" ] MCTruthStream.Output = "DATAFILE='MCTruth.sim' TYP='POOL_ROOTTREE' OPT='RECREATE'" gs.Members += [ SimInit(), gtos, MCTruthStream ]
The root file can then be run over with an MCTupleTool in DaVinci (with certain restrictions, i.e. only tools which only access 4-vectors will run…)
You can run EvtGen standalone, letting the particles decay at rest. This is very fast, as no underlying event has to be generated. A prototype file could look like: <code python> from Configurables import Generation Generation().EventType = 11114001 from Configurables import StandAloneDecayTool Generation().SampleGenerationTool = “StandAloneDecayTool”; Generation().addTool( StandAloneDecayTool ) Generation().StandAloneDecayTool.ProductionTool = “PythiaProduction”;
from Configurables import ToolSvc from Configurables import EvtGenDecay
ToolSvc().addTool( EvtGenDecay ) ToolSvc().EvtGenDecay.UserDecayFile =“$DECFILESROOT/dkfiles/Bd_Kstmumu=DecProdCut.dec” Generation().StandAloneDecayTool.SignalPIDList = [ 511,-511 ] <code>