| Summary: | energy conservation problem in tau decays (G4Exception) | ||
|---|---|---|---|
| Product: | Geant4 | Reporter: | frank.gaede |
| Component: | processes/hadronic | Assignee: | dennis.herbert.wright |
| Status: | RESOLVED FIXED | ||
| Severity: | major | CC: | marko.petric |
| Priority: | P4 | ||
| Version: | 10.3 | ||
| Hardware: | All | ||
| OS: | All | ||
Hi, is there any progress or news on this issue? Cheers, Marko I just started looking at this. Will keep you informed of progress. This is the same problem as in bug report 2053, where the fix is described. It was implemented in Geant4 10.4 p02. Using your macro I verified that there is no longer a crash for taus using this fix. |
We observed crashes in our simulation for the ILD detector at the ILC using geant4 10.3.p02 when simulating e+e- interactions that contain taus in the final state. Tracking down the problem we realized that it also occurs for single taus created with the particle gun ( also using other geant versions). Finally we saw that the problem also occurs using a very simple detector from the basic example B2. The problem seems to be that at some point there are pions created that have extremely (unphysically) high energies, which eventually causes G4Exceptions like this one: -------- EEEE ------- G4Exception-START -------- EEEE ------- *** G4Exception : had005 issued by : G4HadronicProcess::PostStepDoIt In /afs/desy.de/project/ilcsoft/sw/x86_64_gcc54_ub1604/geant4/10.03.p02/source/processes/hadronic/management/src/G4EnergyRangeManager.cc, line 129: ===> GetHadronicInteraction: No Model found Target element H Z= 1 A= 1 Unrecoverable error in the method ChooseHadronicInteraction of pi-Inelastic TrackID= 3 ParentID= 1 pi- Ekin(GeV)= 4.52933e+19; direction= (-0.0100621,-0.0299595,0.9995) Position(mm)= (-4.92096,-14.652,-2450); material G4_WATER PhysicalVolume <Target> No HadronicInteraction found out *** Fatal Exception *** core dump *** -------- EEEE -------- G4Exception-END --------- EEEE ------- *** G4Exception: Aborting execution *** The macro used to provoke this is error is: /run/initialize # set target and chamber material # /B2/det/setTargetMaterial G4_WATER /B2/det/setChamberMaterial G4_Ar /run/beamOn 3 # # set a magnetic field and max allowed step length # 3 event with printing hits # /globalField/verbose 1 /globalField/setValue 5.2 0 0 tesla /B2/det/stepMax 1.0 mm /gun/energy 3.3 MeV # # muon 300 MeV in the direction (0.,0.,1.) # 3 event with detailed printing # /gun/particle tau- /gun/energy 50 GeV /run/beamOn 3000 The problem was reproduced on different OS versions (SL6, ubuntu 1604, macos).