adds Heavy Ion initialization to Pythia

[michael-pitt]

PR description:

This PR allows initiating the Pythia event generator with ions. The fragment should contain:

generator = cms.EDFilter("Pythia8ConcurrentGeneratorFilter",
   ...
   HeavyIonInitialState = cms.PSet(),
   ...
)

and the user can set up Beams:idA and Beams:idB manually.

PR validation:

Validated with CMSSW_15_0_X

[cmsbuild]

cms-bot internal usage

[cmsbuild]

-code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-48414/45314

• There are other open Pull requests which might conflict with changes you have proposed:
  • File GeneratorInterface/Pythia8Interface/plugins/Pythia8Hadronizer.cc modified in PR(s): Fix cross section when using ResonanceDecayFilter #46725, Pythia8 ResonanceDecayFilter Fix #48383

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-48414/45314/code-format.patch
  e.g. curl -k https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-48414/45314/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-48414/45317

• There are other open Pull requests which might conflict with changes you have proposed:
  • File GeneratorInterface/Pythia8Interface/plugins/Pythia8Hadronizer.cc modified in PR(s): Fix cross section when using ResonanceDecayFilter #46725, Pythia8 ResonanceDecayFilter Fix #48383

[cmsbuild]

A new Pull Request was created by @michael-pitt for master.

It involves the following packages:

• GeneratorInterface/Pythia8Interface (generators)

@bbilin, @cmsbuild, @lviliani, @menglu21, @mkirsano can you please review it and eventually sign? Thanks.
@alberto-sanchez, @mkirsano this is something you requested to watch as well.
@antoniovilela, @mandrenguyen, @rappoccio, @sextonkennedy you are the release manager for this.

cms-bot commands are listed here

[stahlleiton]

@michael-pitt : It looks like there are some changes done in the master branch PR that are not related to the backport PR #48412. Maybe some unwanted changes were dragged when you moved from 15_0_X to master branch?

[cmsbuild]

-code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-48414/45327

• There are other open Pull requests which might conflict with changes you have proposed:
  • File GeneratorInterface/Pythia8Interface/plugins/Pythia8Hadronizer.cc modified in PR(s): Fix cross section when using ResonanceDecayFilter #46725, Pythia8 ResonanceDecayFilter Fix #48383

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-48414/45327/code-format.patch
  e.g. curl -k https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-48414/45327/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-48414/45329

• There are other open Pull requests which might conflict with changes you have proposed:
  • File GeneratorInterface/Pythia8Interface/plugins/Pythia8Hadronizer.cc modified in PR(s): Fix cross section when using ResonanceDecayFilter #46725, Pythia8 ResonanceDecayFilter Fix #48383

[cmsbuild]

Pull request #48414 was updated. @bbilin, @cmsbuild, @lviliani, @menglu21, @mkirsano can you please check and sign again.

[michael-pitt]

@stahlleiton I ran code-format suggested by the bot, and it modify the file content. I just restored to the master version, and the bot starts to complain again. I've restored the previous commit. (strangely in 15_0_X cmsbuild bot is happy)

[mandrenguyen]

please test
although no changes to regular workflows expected.

[cmsbuild]

+1

Size: This PR adds an extra 16KB to repository
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-3f1042/46937/summary.html
COMMIT: 5f124f5
CMSSW: CMSSW_15_1_X_2025-06-26-1100/el8_amd64_gcc12
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/48414/46937/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• You potentially added 1 lines to the logs
• Reco comparison results: 10 differences found in the comparisons
• DQMHistoTests: Total files compared: 50
• DQMHistoTests: Total histograms compared: 4065619
• DQMHistoTests: Total failures: 101
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 4065498
• DQMHistoTests: Total skipped: 20
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 49 files compared)
• Checked 215 log files, 184 edm output root files, 50 DQM output files
• TriggerResults: no differences found

[mandrenguyen]

@cms-sw/generators-l2 this looks pretty straightforward. Can you sign please?

[lviliani]

+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. @mandrenguyen, @sextonkennedy, @rappoccio, @antoniovilela (and backports should be raised in the release meeting by the corresponding L2)

[mandrenguyen]

+1