Sub-event aware genJet and parton matching for HI miniAOD

[mandrenguyen]

PR description:

For PbPb generators such as Hydjet we cluster the genJets for each nucleon-nucleon interaction separately. This is done by SubEventGenJetProducer.cc, which gives collections like ak4HiGenJets, already in use in heavy-ion workflows.
In order to do a sensible genJet-recoJet association in PAT, one needs additional procedures that depends on what type of MC is run (ditto for parton association).
For "minimum-bias" generation (a single PbPb event), one needs a cleaning procedure to avoid matching energetic recoJets to incidental overlapping low pT genJets.
For "embedded mode" where we overlay a pp generator (e.g., pythia) onto a PbPb event, we need to use the gen info from the signal event only, despite the fact that we store both the signal and background event in genParticles.

The code modifications consist of:

• The genJetSubEvent modifier was added, and activated for all MB Hydjet RelVal worklows that use the pp reconstruction (the older --scenario HeavyIons workflows are not able to run miniAOD).
• Producers were added to filter out the signal gen information from genParticles. These are active if the above modifier is not called. In a pp event without event overlay, the code will return the usual gen info.
• A counter was added to PATGenJetSlimmer.cc such that it no longer assumes pT-ordered genJets, which is not the case for the sub-event genJet producer
• SubEventGenJetProducer no longer produces a collection of BasicJets, which were not used for anything, and were causing trouble for modules that don't get by type.
• slimmedGenJets now takes as input the heavy-ion style genJets
• slimmedGenJetsFlavourInfos was disactivated, since it doesn't work for sub-event genJets. It's not consumed by any downstream module in heavy-ion wfs.

PR validation:

Tested with 158, 159, 158.01 and 301.

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

Before submitting your pull requests, make sure you followed this checklist:

• verify that the PR is really intended for the chosen branch
• verify that changes follow CMS Naming, Coding, And Style Rules
• verify that the PR passes the basic test procedure suggested in the CMSSW PR instructions

[cmsbuild]

The code-checks are being triggered in jenkins.

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-31698/18857

• This PR adds an extra 88KB to repository

• There are other open Pull requests which might conflict with changes you have proposed:

  • File Configuration/PyReleaseValidation/python/relval_standard.py modified in PR(s): update of "DisplacedSUSY" relvals for TRK and EXO validation of displaced tracks, for Run 3 and Phase 2 #31692
  • File Configuration/PyReleaseValidation/python/relval_steps.py modified in PR(s): Nano gen dqm #31591, update of "DisplacedSUSY" relvals for TRK and EXO validation of displaced tracks, for Run 3 and Phase 2 #31692
  • File Configuration/StandardSequences/python/Eras.py modified in PR(s): Ecal phase2 sim reco 11 1 x #29386
  • File PhysicsTools/PatAlgos/python/producersHeavyIons/heavyIonJets_cff.py modified in PR(s): Legacy csvV2 calibrations for 2018 PbPb data #31660, Bad PF candidate filter for 2018 PbPb data #31668
  • File PhysicsTools/PatAlgos/python/slimming/miniAOD_tools.py modified in PR(s): Add anti-electron tauID for phase2 #31470, Legacy csvV2 calibrations for 2018 PbPb data #31660

[cmsbuild]

A new Pull Request was created by @mandrenguyen (Matthew Nguyen) for master.

It involves the following packages:

Configuration/Eras
Configuration/PyReleaseValidation
Configuration/StandardSequences
PhysicsTools/PatAlgos
RecoHI/HiJetAlgos
RecoJets/JetProducers

@perrotta, @jordan-martins, @chayanit, @wajidalikhan, @kpedro88, @cmsbuild, @silviodonato, @franzoni, @slava77, @jpata, @qliphy, @santocch, @fabiocos, @davidlange6 can you please review it and eventually sign? Thanks.
@rappoccio, @gouskos, @yslai, @felicepantaleo, @hatakeyamak, @emilbols, @Martin-Grunewald, @ahinzmann, @peruzzim, @seemasharmafnal, @mmarionncern, @makortel, @smoortga, @dgulhan, @jdolen, @slomeo, @ferencek, @yetkinyilmaz, @GiacomoSguazzoni, @rovere, @VinInn, @jdamgov, @nhanvtran, @gkasieczka, @schoef, @mtosi, @fabiocos, @clelange, @riga, @jazzitup, @JyothsnaKomaragiri, @yenjie, @lecriste, @kurtejung, @gpetruc, @mariadalfonso, @andrzejnovak this is something you requested to watch as well.
@silviodonato, @dpiparo, @qliphy you are the release manager for this.

cms-bot commands are listed here

[slava77]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.

• CMSSW_11_2_X_2020-10-07-2300/slc7_amd64_gcc820: https://cmssdt.cern.ch/jenkins/job/ib-run-pr-tests/9797/console Started: 2020/10/08 07:47

[cmsbuild]

+1
Tested at: b270197
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-bdae31/9797/summary.html
CMSSW: CMSSW_11_2_X_2020-10-07-2300
SCRAM_ARCH: slc7_amd64_gcc820

[cmsbuild]

Comparison job queued.

[chayanit]

+1

[perrotta]

Checked wf 158 with and without the genJetSubEvent modifier, and everything behaves as expected: with that modifier the current (i.e. as in the baseline) slimmedGenJets in miniAOD are reproduced, while when it gets removed hiSignalGenJets are the source for those slimmedGenJets, as they should.

The net result is that when the hiSignalGenJets are the source for the slimmedGenJets, those slimmedGenJets have a larger set of partons from which they can be built, and therefore the slimmedGenJets size increases in miniAOD, as expected:

 Checking process _ step3_MB_inMINIAODSIM.root and step3_inMINIAODSIM.root with useUnpacked=no (if above 1 or 1%):
Compare packed values
-----------------------------------------------------------------
   or, B         new, B      delta, B   delta, %   deltaJ, %    branch 
-----------------------------------------------------------------
  32277.0 ->     39497.0       7220     20.1   1.05     recoGenJets_slimmedGenJets__RECO.
-------------------------------------------------------------
   684470 ->      691690       7220             1.1     ALL BRANCHES

[perrotta]

+1

• Updates are consistent with the expectations described in the PR descriptions
• No differences in reco/miniAOD outputs in the workflows tested automatically, while changes are there for the HI workflows in "embedded mode". The difference being only in the genJet collection in miniAOD, it is then probably not necessary to have one of those workflows included in the automatic tests: but I'd let the HI responsible think about it

[kpedro88]

+upgrade

[silviodonato]

+operations

[silviodonato]

merge

[santocch]

+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 be automatically merged.