Bug fix in Geant4 stepping and stacking actions

[civanch]

PR description:

In an attempt to optimize Run-3 simulation and fix minor problem in Geant4 user actions a logical bug was introduced, which affect calorimeter responses. The problem was reported first by @abdoulline . In this PR the logic of filters at each step (SteppingAction) has been fixed. A minor problem is also fixed in StackingAction, which is called for each new secondary particle.

The level of the problem, identified by @abdoulline is 2-3% reduction of energy deposition in calorimeters. With the test-beam 2006 the effect is even more and may illustrated for pi- projectile:

In the proposed fix the situation return back to normal:

[cmsbuild]

-code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-33923/22996

• This PR adds an extra 20KB to repository

Code check has found code style and quality issues which could be resolved by applying following patch(s)

• code-format:
  https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-33923/22996/code-format.patch
  e.g. curl https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-33923/22996/code-format.patch | patch -p1
  You can also run scram build code-format to apply code format directly

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-33923/22997

• This PR adds an extra 20KB to repository

[cmsbuild]

A new Pull Request was created by @civanch (Vladimir Ivantchenko) for master.

It involves the following packages:

SimG4Core/Application

@cmsbuild, @civanch, @mdhildreth can you please review it and eventually sign? Thanks.
@makortel, @cvuosalo, @rovere, @fabiocos, @slomeo this is something you requested to watch as well.
@silviodonato, @dpiparo, @qliphy you are the release manager for this.

cms-bot commands are listed here

[civanch]

please test

[civanch]

@bsunanda , FYI

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-bbb421/15489/summary.html
COMMIT: 4f5e150
CMSSW: CMSSW_12_0_X_2021-05-31-1100/slc7_amd64_gcc900
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/33923/15489/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• No significant changes to the logs found
• ROOTFileChecks: Some differences in event products or their sizes found
• Reco comparison results: 47974 differences found in the comparisons
• DQMHistoTests: Total files compared: 37
• DQMHistoTests: Total histograms compared: 2650486
• DQMHistoTests: Total failures: 284695
• DQMHistoTests: Total nulls: 231
• DQMHistoTests: Total successes: 2365538
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.908 KiB( 36 files compared)
• DQMHistoSizes: changed ( 10224.0 ): -0.479 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 250202.181 ): -0.645 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 7.3 ): 0.495 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 8.0 ): 1.537 KiB SiStrip/MechanicalView
• Checked 155 log files, 37 edm output root files, 37 DQM output files
• TriggerResults: found differences in 11 / 36 workflows

[abdoulline]

@civanch thank you for the fix!
My private 2021 pion gun test confirms your TB 2006 results after applying the fix (within stat. errors) :
https://cms-cpt-software.web.cern.ch/cms-cpt-software/General/Validation/SVSuite/HCAL/calo_scan_single_pi/12_X/12_0_0_pre2_run3_PR33923_vs_12_0_0_pre1_run3_SinglePi/SimHitsTask_emean_vs_ieta_EH.gif

[civanch]

+1

the problem was that all stopping particles (e+, pi-,.. ) were killed before reaction at rest is happens. The effect is in calorimeters and this confirms, that stopping processes have to be simulated.

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next master IBs (tests are also fine). This pull request will now be reviewed by the release team before it's merged. @silviodonato, @dpiparo, @qliphy (and backports should be raised in the release meeting by the corresponding L2)

[silviodonato]

+1