HDGeant4 Meeting, February 9, 2021

From GlueXWiki
Jump to: navigation, search

HDGeant4 Meeting
Tuesday, February 9, 2021
3:00 pm EST
BlueJeans: 968 592 007


  1. Announcements
  2. Review of minutes from the last meeting (all)
  3. Issues on GitHub
  4. Pull Requests on GitHub
  5. Action Item Review


Present: Alex Austregesilo, Tegan Beattie, Sean Dobbs, Mark Ito (chair), Igal Jaegle, Richard Jones, Zisis Papandreou, Simon Taylor, Nilanga Wickramaarachchi, Beni Zihlmann

There is a recording of this meeting on the BlueJeans site. Log into the BlueJeans site first to gain access (use your JLab credentials).


The Collaboration Meeting Agenda has been announced and there are no slots for HDGeant4-related topics scheduled. If folks have ideas for topics that should be presented to the Collaboration, please contact Mark.

Review of minutes from the last meeting

We went over the minutes from January 26 without significant comment.

G3/G4 Comparison

Tegan presented simulation results on BCAL response separately for charged pions and protons. For each particle type he compared responses with

  1. Standard HDGeant4
  2. The bcal_nolight_heavy_rtj branch of HDGeant4 (NHL)
  3. hdgeant (GEANT3) with HADR1
  4. hdgeant (GEANT3) with HADR4

From the discussion:

  • Particles were generated between 10 and 40 degrees in polar angle an with momenta from 400 MeV to 2.0 GeV.
  • The frequency of secondary electrons shows a difference of almost a factor of two between the two HDGeant4 simulations with NHL higher than the standard. We did not come up with a good explanation for this.
  • Sean remarked on the long late timing tail for secondary electrons[?] in HADR1.
  • Beni suggested making a 2D histogram of the number of hits in a cluster vs. "BCAL Shower Time - Truth Shower Time". He was suspicious that the tail may be coming from single- or few-counter clusters.
  • Richard wondered how energy thresholds are treated in the detector "smearing."
  • Sean suggested looking at individual hit times vs. the true shower time. This distribution might tell us something.
  • For protons there appears to be a difference in the number of produced neutrons with HADR4 compared to the same population when plotted as a function of time. Many of the former and very few of the latter.
  • Sean and Richard advocated starting to do comparisons with data. Richard thought that using exclusive ρ events might give a relatively uniform and plentiful sample of protons hitting the BCAL. Sean suggested that Alex pass such a sample on the Tegan for study.

Other Issues on GitHub

We went through the list.