Please find the minutes for the meeting held earlier this week here
<https://halldweb.jlab.org/wiki/index.php/HDGeant4_Meeting,_December_17,_2019#Minutes>
and below.
HDGeant4 Meeting, December 17, 2019, Minutes
Present:
* *CMU: * Naomi Jarvis
* *JLab: * Alex Austregesilo, Mark Dalton, Colin Gleason, Mark Ito
(chair), Keigo Mizutani, Simon Taylor
* *UConn: * Richard Jones
There is a recording of this meeting <https://bluejeans.com/s/Eum3E/> on
the BlueJeans site. Use your JLab credentials to get access.
Review of Minutes from the December 3 Meeting
We went over the minutes
<https://halldweb.jlab.org/wiki/index.php/HDGeant4_Meeting,_December_3,_2019#Minutes>.
Alex will close the issue on neutron generation
<https://github.com/JeffersonLab/HDGeant4/issues/125>.
genBH Output Format
At the last software meeting Mark D. reported problems reading the
output from the genBH generator. The code is in the HDGeant4 repository.
Richard was able to reproduce the problem and submitted a pull request
<https://github.com/JeffersonLab/HDGeant4/pull/135> that fixes the problem.
Issues on GitHub
We went over the issues
<https://github.com/JeffersonLab/HDGeant4/issues>. Most of the time was
spent discussion Issue #111
<https://github.com/JeffersonLab/HDGeant4/issues/111>, "Difference in
Acceptance between G3 and G4". Colin led the discussion.
* Colin went back and revisited his study from last May with recent
versions of software.
* When looking at the comparison of efficiency as a function of eta-pi
mass, the agreement is between G3 and G4 is reasonable, but when
viewed as a function of cosθ_GJ there is a noticeable difference
between the forward and backward directions (at 7:17 in the
recording). This is similar to the results of the original study and
the initial cause of concern. Colin noted that the data is more
similar to the G3 efficiency as opposed to that for G4.
* Mark Dalton pointed out that in this and other efficiency studies,
the overall event acceptance is less that that one would expect from
single particle studies.
* After sorting through some some confusion, we concluded that the
single particle yield comparisons that were shown are actually after
the events are accepted by the analysis library. This means that
they reflect not only the efficiency of the particle shown, but the
overall event efficiency. In particular differences in the
efficiencies for one type of particle will effect the apparent
comparative yield of other particle types.
* Alex suggested that the problematic effect might also the the effect
of timing cuts placed on charged particles in the calorimeters, a
problem he illustrated in his post to Issue #93
<https://github.com/JeffersonLab/HDGeant4/issues/93>. Colin will
pursue this possibility, in particular repeating the analysis with
looser timing cuts on matching between charged tracks and
calorimeter clusters.
* Eugene Chudakov made a suggestion to Colin: do the G3 vs. G4
comparison with the same input events and see where the differences
occur on an event-by-event basis. Perhaps a pattern will emerge.
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* This page was last modified on 20 December 2019, at 12:17.
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