Fixed fast sim sampling of ECAL hits

[civanch]

PR description:

In this PR a contradiction between "FineCalo" mechanism of MCTruth and GFlash hit sampling in ECAL is resolved. In the case of GFlash sampling of hits, there is no Geant4 touchable defined, which provoke a crash.

Another fix is introduce in low-energy GFlash model.

These modifications should not affect baseline simulation.

PR validation:

private

[civanch]

type bug-fix

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-34485/23946

• This PR adds an extra 28KB to repository

[cmsbuild]

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

It involves the following packages:

• SimG4CMS/Calo (simulation)
• SimG4Core/Application (simulation)

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

cms-bot commands are listed here

[civanch]

please test

[civanch]

@bsunanda , this PR is needed, because it is not possible simultaneously use GFlash approach and check touchable.

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-7efd6b/16814/summary.html
COMMIT: e8e72ea
CMSSW: CMSSW_12_0_X_2021-07-13-2300/slc7_amd64_gcc900
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/34485/16814/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
• Reco comparison results: 4 differences found in the comparisons
• DQMHistoTests: Total files compared: 38
• DQMHistoTests: Total histograms compared: 2786302
• DQMHistoTests: Total failures: 7
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 2786273
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 37 files compared)
• Checked 160 log files, 37 edm output root files, 38 DQM output files
• TriggerResults: no differences found

[civanch]

+1

[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, @perrotta (and backports should be raised in the release meeting by the corresponding L2)

[qliphy]

+1