[12_2_X] Push_back 0th weight manually, prevent duplication of PS weights in P8.30x

[SiewYan]

PR description:

Echoing PR's description from #38012, created by @SanghyunKo.
"
The weight storage logic in Pythia8 had been changed since 8.30x version, causing the duplication of PS weights in CMS. This PR prevents weight duplication by setting Pythia8ToHepMC::set_store_weights(false) and keeps the old weight structure the same as in UL by push_back 0th weight manually. Fixes #36705
"

The PR is needed for sample production for Early analysis, which rely on PS. @agrohsje

The Issue and PR involves:

• Issue : 134 PS weights instead of 46 in Pythia 8.3  #36705
• [12_5_X] : Push_back 0th weight manually, prevent duplication of PS weights in P8.30x #38012
• [12_4_X] : [12_4_X] Push_back 0th weight manually, prevent duplication of PS weights in P8.30x #38057

PR validation:

Testing with the workflow 555, 556 (should reduce the number of weights from 134 to 46)

if this PR is a backport please specify the original PR and why you need to backport that PR:

backport of PR #38012

[cmsbuild]

A new Pull Request was created by @SiewYan (Siewyan Hoh 何守仁) for CMSSW_12_2_X.

It involves the following packages:

• GeneratorInterface/Pythia8Interface (generators)

@SiewYan, @mkirsano, @Saptaparna, @cmsbuild, @GurpreetSinghChahal, @alberto-sanchez can you please review it and eventually sign? Thanks.
@alberto-sanchez, @mkirsano this is something you requested to watch as well.
@perrotta, @dpiparo, @qliphy you are the release manager for this.

cms-bot commands are listed here

[SiewYan]

please test workflow 555, 556

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-44e330/25280/summary.html
COMMIT: 318fea2
CMSSW: CMSSW_12_2_X_2022-06-05-0000/slc7_amd64_gcc900
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmssw/38248/25280/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

@slava77 comparisons for the following workflows were not done due to missing matrix map:

• /data/cmsbld/jenkins/workspace/compare-root-files-short-matrix/data/PR-44e330/555.0_DYTollJets_NLO_Mad_13TeV_py8+DYToll012Jets_5f_NLO_FXFX_Madgraph_LHE_13TeV+Hadronizer_TuneCP5_13TeV_aMCatNLO_FXFX_5f_max2j_max0p_LHE_pythia8+HARVESTGEN2
• /data/cmsbld/jenkins/workspace/compare-root-files-short-matrix/data/PR-44e330/556.0_TTbar_NLO_Pow_13TeV_py8+TTbar_Pow_LHE_13TeV+Hadronizer_TuneCP5_13TeV_powhegEmissionVeto2p_pythia8+HARVESTGEN2

Summary:

• No significant changes to the logs found
• Reco comparison results: 0 differences found in the comparisons
• DQMHistoTests: Total files compared: 44
• DQMHistoTests: Total histograms compared: 3253004
• DQMHistoTests: Total failures: 0
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 3252982
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 43 files compared)
• Checked 183 log files, 37 edm output root files, 44 DQM output files
• TriggerResults: no differences found

[Saptaparna]

+1
@SiewYan: do we need further tests?

[SiewYan]

Hello @Saptaparna , it is hard to tell if the backport is working, given the targeted workflows are not run due to the missing matrix map.

@perrotta , in this case, what do you propose to proceed? Thanks.

[qliphy]

@SiewYan Similarly as done in master, you may do some local checks?

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_12_2_X IBs (tests are also fine) and once validation in the development release cycle CMSSW_12_5_X is complete. This pull request will now be reviewed by the release team before it's merged. @perrotta, @dpiparo, @qliphy (and backports should be raised in the release meeting by the corresponding L2)

[SiewYan]

@qliphy

Local test:

• Setup with /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmssw/38248/25280/install.sh
• wf test 556 : runTheMatrix.py -e -l 556

The results is expected , reduced to 46 wieghts x 10 events = 460 entry:

[qliphy]

+1

[agrohsje]

hi @qliphy , @perrotta . do you mind building a new release with this PR? we might produce 12_2 for early top analysis. thanks so much.

[qliphy]

@agrohsje Sure. Would you please give a bit more details about the production campaign?

[agrohsje]

The idea would be to use Run3Winter22wmLHEGS and friends.

[qliphy]

@agrohsje https://github.com/cms-sw/cmssw/releases/CMSSW_12_2_4_patch1 is ready