Disable ZDC digitization for simulation.

[hjbossi]

PR description:

This PR disables ZDC digitization in simulation in order to prevent runtime errors (see #43582). The ZDC is not incorporated fully into CMSSW and therefore this has no impact on analysis. Additionally, an era modifier has been implemented such that the ZDC digitization can be re-implemented for special cases in the event that it is needed.

PR validation:

The PR validation is documented in this dropbox paper and was tests using 2025 MC workflow.

If this PR is a backport please specify the original PR and why you need to backport that PR. If this PR will be backported please specify to which release cycle the backport is meant for:

This PR will be used to avoid errors in the 2025 MC workflow, so will need a backport to 15_1_X.

Tagging HIN colleagues: @mandrenguyen
Tagging HCAL colleagues:@abdoulline @yildirayk

[cmsbuild]

cms-bot internal usage

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-49612/47146

[cmsbuild]

A new Pull Request was created by @hjbossi for master.

It involves the following packages:

• Configuration/Eras (operations)
• SimCalorimetry/HcalSimProducers (simulation)

@civanch, @cmsbuild, @davidlange6, @fabiocos, @ftenchini, @kpedro88, @mandrenguyen, @mdhildreth can you please review it and eventually sign? Thanks.
@Martin-Grunewald, @abdoulline, @bsunanda, @fabiocos, @makortel, @mariadalfonso, @rovere, @sameasy this is something you requested to watch as well.
@ftenchini, @mandrenguyen, @sextonkennedy you are the release manager for this.

cms-bot commands are listed here

[kpedro88]

please test

[cmsbuild]

+1

Size: This PR adds an extra 28KB to repository
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-de2f5e/49918/summary.html
COMMIT: b34d1d5
CMSSW: CMSSW_16_0_X_2025-12-11-2300/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/49612/49918/install.sh to create a dev area with all the needed externals and cmssw changes.

The following merge commits were also included on top of IB + this PR after doing git cms-merge-topic:

• @smorovic [DAQ] fix hang in single stream and thread mode #49599

You can see more details here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-de2f5e/49918/git-recent-commits.json
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-de2f5e/49918/git-merge-result

Comparison Summary

Summary:

• You potentially removed 7 lines from the logs
• ROOTFileChecks: Some differences in event products or their sizes found
• Reco comparison results: 40339 differences found in the comparisons
• Reco comparison had 4 failed jobs
• DQMHistoTests: Total files compared: 53
• DQMHistoTests: Total histograms compared: 4273241
• DQMHistoTests: Total failures: 65355
• DQMHistoTests: Total nulls: 2
• DQMHistoTests: Total successes: 4207864
• DQMHistoTests: Total skipped: 20
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: -2.016 KiB( 52 files compared)
• DQMHistoSizes: changed ( 10224.0 ): 0.234 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 13034.0 ): 0.176 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 17034.0 ): 0.542 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 250202.181 ): 0.305 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 25202.0 ): 0.352 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 7.3 ): 0.838 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 8.0 ): -4.463 KiB SiStrip/MechanicalView
• Checked 227 log files, 198 edm output root files, 53 DQM output files
• TriggerResults: found differences in 5 / 51 workflows

[abdoulline]

Changes in Digitization are expected due to altered rndm sequence.
In line with a similar ZDC Digitization disabling, previously implemented (in 14_0_X only):
#46282 (comment)

[makortel]

This file looks like a better place for it would be in Configuration/ProcessModifiers, because it (or its use) seems to be independent of data taking conditions.

[hjbossi]

Thank you for the suggestion, this is implemented in the latest commit!

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-49612/47165

• Found files with invalid states:
  • Configuration/Eras/python/Modifier_zdcDigi_cff.py:
    • Added: b34d1d5
    • Deleted: a44f28f

[cmsbuild]

Pull request #49612 was updated. @civanch, @cmsbuild, @davidlange6, @fabiocos, @ftenchini, @kpedro88, @mandrenguyen, @mdhildreth can you please check and sign again.

[kpedro88]

please test

[cmsbuild]

+1

Size: This PR adds an extra 32KB to repository
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-de2f5e/49966/summary.html
COMMIT: a44f28f
CMSSW: CMSSW_16_0_X_2025-12-13-1100/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/49612/49966/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• You potentially removed 5 lines from the logs
• Reco comparison results: 40337 differences found in the comparisons
• Reco comparison had 4 failed jobs
• DQMHistoTests: Total files compared: 53
• DQMHistoTests: Total histograms compared: 4273241
• DQMHistoTests: Total failures: 65360
• DQMHistoTests: Total nulls: 2
• DQMHistoTests: Total successes: 4207859
• DQMHistoTests: Total skipped: 20
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: -2.016 KiB( 52 files compared)
• DQMHistoSizes: changed ( 10224.0 ): 0.234 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 13034.0 ): 0.176 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 17034.0 ): 0.542 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 250202.181 ): 0.305 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 25202.0 ): 0.352 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 7.3 ): 0.838 KiB SiStrip/MechanicalView
• DQMHistoSizes: changed ( 8.0 ): -4.463 KiB SiStrip/MechanicalView
• Checked 227 log files, 198 edm output root files, 53 DQM output files
• TriggerResults: found differences in 5 / 51 workflows

[hjbossi]

@makortel if these changes look okay to you, maybe we can try to merge this?

[makortel]

Looks good to me.

[kpedro88]

+simulation

[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. @sextonkennedy, @ftenchini, @mandrenguyen (and backports should be raised in the release meeting by the corresponding L2)

[mandrenguyen]

+1