CERN Accelerating science

Minutes of the Hadronic Working Group - 11 May 2006

Present: John Apostolakis, Gunter Folger, Aatos Heikinnen, Vladimir Ivantchencko,
Tatsumi Koi, Mikhail Kossov, Ilya Agapov (guest), Dennis Wright
Apologies from: Nikolai Starkov


Meeting starts at 17:10 CET (8:10 PST).

  • Reports:
    • Gunter Folger (several reports from LCG physics validation meeting linked to agenda)
      • For energies higher than 100 GeV the longitudinal shower profile is too short. It is better for LHEP than QGSP.
      • Reasons are being explored. Not much data to compare with for inelastic cross sections
      • In LHEP, there are more pi- than in QGSP, and more neutrons as well
      • Cross sections are being checked as a possible cause
      • In pion rapidity there is a broad flat peak in QGSP, but three sharper peaks in LHEP. The three peak structure is probably not correct.
      • In data comparisons, all Geant4 models (even cascades) have too few neutrons

    • Ilya Agapov - currently working for ILC on backgrounds and radiation protection. Will contribute validations for gamma and electro-nuclear processes. Currently looking at 1 GeV electrons on thick targets (10 radiation lengths) and the resulting neutron fluxes. Differences from data appear at 6-8 MeV. Between 10 and 100 MeV things look OK. The physics list used was LHEP, so better low energy behavior can be obtained by using the high precision neutron package.

    • Tatsumi Koi - please turn in the validation sheets for any comparisons you have done. I am ready to start a compilation of them.

    • Vladimir Ivantchencko (see links from agenda)
      • G4Nucleus still uses the old atomic mass values. Should remove G4AtomicMass and replace with G4IonTable.
      • There is no charge exchange process in the QBBC physics list. We need a separate charge exchange model which itself would be divided into coherent and incoherent
      • in comparing QBBC and other physics lists, several problems were noted, including:
        • lack of Coulomb barrier in LHEP
        • 1 keV spikes in K- capture and LHEP neutrons
      • Should QBBC physics list be released for 8.1? Need to get response from internal users first. Do we not already have too many physics lists? Need more discussion with people outside hadronic group. Dennis will organize a meeting.
      • An ion example is proposed for inclusion in the extended/hadronic examples. It was developed for an ion therapy study, and should be useful for learning about setting up heavy ion experiments.

    • Mikhail Kossov
      • Cross section review is continuing
      • There will be a CHIPS-based quasi-elastic model for the coming release
      • There will not be a heavy nucleus model for this release

    • Report by Nikolai Starkov inserted into minutes:
      • I have prepared the new version of HE hadron-nucleus elastic classes which do not need files of data. But now it is only for A less than 100. Before June I will send this variant to Vladimir (Ivantchenko) who tests elastic procesees now. Later I will optimize heavier nuclei.
      • On the request of Vladimir I prepared new function having another interface with the kernel of GEANT4 (without function ApplyYourself). Now he is testing this function.
      • I expanded classes to D, T and He3 but now only in draft version. It is nessesary to ajust nuclei parameters from the comparision with elastic experiment. I hope to finish this procedure before July.

    • Dennis Wright (see link to agenda)
      • Several problems with the Low Energy Parameterized models were fixed. They all had to do with non-conservation of energy. Next I will look at the High Energy Parameterized models. So far the fixed versions have not affected the shower shapes. This code will be included in the 8.1 release.
  • Old and New members
    • Dennis has been talking to Vicente Lara about re-starting his Geant4 participation. He is still interested in developing the pre-compound model.
    • Aatos:
      • We will organize a 'INCL-Geant4' mini-workshop at CERN June 19th-20th. All Geant4 hadronic group members are welcome. Please register directly to Aatos if you are attending.
      • We have now received the Fortran code INCL4 including ABLA. (Fortran version of INCL5 is in preparation, and Liede group has promised to provide also that in due time.) Developers of Liege cascade have been very active, and I consider them as potential new collaborators in the Geant4 hadronic working group. Let me remind you the Liege group has very strong theoretical expertise and access to latest data.
      • Original developers include CEA (Alain Boudard and Yair Yariv), University of Liege (Joseph Cugnon) and GSI (Karl-Heinz Schmidt). It seems that the mini-workshop will have a good representation from these institutes.