Simulation Project Leaders Meeting
26-February-2013

==== Attendees (virtual meeting)

John Apostolakis (JA), Alfredo Ferrari (AF), Witold Pokorski (WP),
Rob Veenhof (RV), Gabriele Cosmo (GC).

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==== Minutes


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==== Simulation physics validation & framework - Witek

- Nothing to report.

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==== Generator services - Witek 

- GENSER:
  o The GENSER team is now moving the build system to the new machinery
    based on CMake. This will allow generators to be installed the same way
    as the LCG external software, possibly by the same team of librarians
    that is looking after the LCG external software.
    The CMake files have been already prepared for 17 generators (35% of
    the whole GENSER). Setups for new generators are being migrated each
    day. Expecting to complete the migration within a month.
  o New generators installed: photos++-3.52, amcatnlo-1.1, thepeg-1.8.3,
    hepmcanalysis-3.4.13, herwig++-2.6.3, sherpa-1.4.3.2, vincia-1.0.29,
    pythia8-175, tauola++-1.1.1a.

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==== Fluka - Alfredo

- No report.

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==== Geant4 - John, Gabriele

- Releases:
  o Patch 1 for Geant4 9.6 was released on February 1st 2013. It included
    the corrected sampling of scattering tail in Urban93 multiple-scattering
    model; the same parameter limit was also added to Urban95 and Urban96
    variants for additional robustness; also included an important fix to
    address incorrect deviation in magnetic field, due to overwriting of
    the final momentum by the multiple-scattering process.
    Additional changes included are: a fix for G4TessellatedSolid on 32-bit
    platforms due to rounding; a fix in hadronic de-excitation in the case
    of Fermi breakup not splitting the nucleus; corrected issues in
    anti-nucleus cross-sections; a fix to restore reproducibility for QBBC
    physics list, and corrected parameters of stainless steel in NIST
    material builder.
- Development:
  o The multi-threaded prototype (Geant4-MT) has been merged into the
    repository trunk and first improvements are being implemented to
    simplify new code, and remove thread-local variables which were deemed
    unnecessary.
  o Plans for 2013 developments have been prepared by working groups and
    will be presented at the next Geant4 Technical Forum.
- Experiments feedback:
  o The fix to the Urban93 multiple-scattering model, to correct unphysical
    angular distribution of multi-GeV electrons for small steps, responsible 
    for cases of large-angle scatters has been deployed to ATLAS. This
    allowed to remove an angle restriction which appeared to affect ATLAS
    simulation (Z -> ee lineshape).
  o Following investigation from LHCb, a problem was identified with kaon
    cross-sections in release 9.5, due to a bug in the CHIPS interface.
    A patch has been provided to LHCb who needed it for their 2012
    production runs based on Geant4 release 9.5.
  o Validation of 9.6.p01 is currently ongoing in CMS. No issues reported
    so far.
- Meetings:
  o The next Geant4 Technical Forum will take place at CERN on March 26th
    and dedicated to finalise the program of work for 2013.
  o The next Geant4 Collaboration Meeting is confirmed to happen in Sevilla
    on September 23-26th.
  o The 9th Geant4 Space Users' Workshop is taking place in Barcelona
    on March 4-6th.
  o User conference and training course for Medicine and Biology
    applications to happen in Bordeaux on October 7-9th.

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==== Garfield - Rob

- Activities: 
  o Ion back flow: simulations by Tokyo colleagues now show quantitatively
    that space charge is a key factor in controlling ion back flow in GEMs.
    The accuracy of the calculations hinges on our understanding of ion
    diffusion.
  o Y.Kalkan, new PhD student in Bursa, will spend the next few months
    assessing current knowledge on ion transport. L.Viehland seems to take
    an active interest in this work.
- Meetings:
  o 30/1-1/2: RD51 mini week, full programme on simulations.
  o 27/2-1/3: TPC meeting in Bonn.
  o 9/4: AIDA lectures in Frascati.
  o End of April: RD51 collaboration meeting.

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==== AOB

Next meeting scheduled for April 30th.