Update 2026 HI MC GT with a new L1T menu - CMSSW_16_1_X

[perrotta]

PR description:

A new GT was prepared in 161X for the 2026 HI MC campaign, as requested in https://cms-talk.web.cern.ch/t/gt-mc-hin-request-for-a-pbpb-run-mc-queue-in-161x/143262/15

The new 2026 HI MC GT is 161X_mcRun3_2026_realistic_HI_v2 and the difference with the previous HI MC GT in autoCond is here (only the L1T menu was updated with respect to the 2025 HI MC GT so far).

PR validation:

(To be) tested in master, and here in the PR tests

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:

backport of #50905

[cmsbuild]

A new Pull Request was created by @perrotta for CMSSW_16_1_X.

It involves the following packages:

• Configuration/AlCa (alca)

@Alejandro1400, @JanChyczynski, @arunhep, @atpathak, @cmsbuild, @perrotta can you please review it and eventually sign? Thanks.
@Martin-Grunewald, @fabiocos, @mmusich, @rsreds, @tocheng, @yuanchao 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

• Backported from Update the 2026 HI MC GT in autoCond with a new L1T menu #50905

[cmsbuild]

cms-bot internal usage

[JanChyczynski]

please test

[mmusich]

backport of #50905

[cmsbuild]

+1

Size: This PR adds an extra 20KB to repository
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-939bcf/53141/summary.html
COMMIT: 7b13230
CMSSW: CMSSW_16_1_X_2026-05-08-1100/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmssw/50906/53141/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• You potentially added 2 lines to the logs
• Reco comparison results: 6 differences found in the comparisons
• DQMHistoTests: Total files compared: 53
• DQMHistoTests: Total histograms compared: 4182125
• DQMHistoTests: Total failures: 61
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 4182044
• DQMHistoTests: Total skipped: 20
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 52 files compared)
• Checked 227 log files, 197 edm output root files, 53 DQM output files
• TriggerResults: no differences found

[perrotta]

+alca

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_16_1_X IBs (tests are also fine) and once validation in the development release cycle CMSSW_17_0_X is complete. 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