Minutes of 10 April 2018 Meeting of Geant4 Technical Forum
Editor: A. Morsch, 10 April 2018
- Starting at 16:00

General introduction and prospects
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+ see slides for details
- Next release December 2018; whether this will be a minor or major release will be decided soon
- Next beta release June 29

Summary of recent patch release & 2018 work plan - non–physics part
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+ see slides for details
- S11 The plan is to phase out G4 geometry and move to VecGeom; but not yet this year
- S12 Fast simulation options will be available via Physics List; was not a user request, but part of general development plans.

Summary of recent patch release & 2018 work plan - EM physics part
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+ see slides for details

Summary of recent patch release & 2018 work plan - Hadronic physics part
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+ see slides for details
- S8 HIJING interface does not yet exist; only validation 
- S9 EPOS is an interesting option since it describes well LHC (pp, pA and AA) data.

Status of open requirements
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+ see slides for details
- S3 ATLAS request from last TF on predefined decays. Otion already exists. Clarification with ATLAS needed.
- 4302-4305 (Radioprotection and Radiophysics): work in progress and part   of working group plan
- 4301 needed feed-back from T2K, contacts have been re-established
- 4002 Reweightable uncertainties for systematic uncertainty estimation: in progress
- 3901 very good progress recently, close to completion
- 4003 Validation of new versions of Geant4: closed

 
**** New Requirements

ATLAS Report
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+ see slides for details
- S4 Small step issue solution proposed by Makoto
- S5 Effect of "Nystrom"-bug likely much smaller in ATLAS than the one seen by ALICE
- S7-8 Suggestion to cut the geometry in smaller pieces


New CMS Requirements
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+ see slides 
- S2: Realistic tau decays: suggestion to use external decayer (Pythia8, ...)
- S3: Inclusion of effects of γ polarization in the high energy EM models. Needs to be implemented before one can decide
whether shower shape effects exist or not. However, shower shape likely to be dominated by low-energy part of the shower.