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Fix in HepMC - G4 interface for displaced SUSY simulation #47165

Closed 24LopezR closed 2 weeks ago

24LopezR commented 2 weeks ago

PR description:

This PR aims to fix two issues affecting SimTracks and SimHits for signal processes involving long-lived smuons.

  1. Handling of daughter particles doesn't take into account the smuon pdgID, leading to duplicated muon SimTracks.
  2. A cut in the z coordinate of the decay point supresses smuon SimTracks for high lifetime signals.

More details about the issue can be found in slide 13 of [1].

PR validation:

The changes have been validated using privately produced signal samples of pair production of long-lived smuons decaying to a muon and a gravitino (smuon->mu+G). More details in slide 14 of [1].

[1] https://indico.cern.ch/event/1476269/#6-plan-for-displaced-dimuon-an

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 needs to be backported to 12_4_X and 13_0_X (for 2022 and 2023 signal sample production)

@civanch

cmsbuild commented 2 weeks ago

cms-bot internal usage

cmsbuild commented 2 weeks ago

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-47165/43398

cmsbuild commented 2 weeks ago

A new Pull Request was created by @24LopezR for master.

It involves the following packages:

@civanch, @cmsbuild, @kpedro88, @mdhildreth can you please review it and eventually sign? Thanks. @bsunanda, @fabiocos, @makortel, @martinamalberti, @rovere, @slomeo this is something you requested to watch as well. @antoniovilela, @mandrenguyen, @rappoccio, @sextonkennedy you are the release manager for this.

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kpedro88 commented 2 weeks ago

please test

cmsbuild commented 2 weeks ago

+1

Size: This PR adds an extra 40KB to repository Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-85c747/43920/summary.html COMMIT: 67d2cc027813991a4540b4183fad349c637d5c85 CMSSW: CMSSW_15_0_X_2025-01-22-1100/el8_amd64_gcc12 User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/47165/43920/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

civanch commented 2 weeks ago

@24LopezR , you misunderstand me. What I propose is following: you to add to g4SimHits only one extra flag "SMUON = False". So, for all other applications nothing will changed. Inside Generator class you check this flag and implement special treatment if it is "true". Special treatment means check of the list of pdgCode corresponding to these particle and disable of check on solid angle. In the case, when you submit simulation job, you customise smuon flag to be true.

24LopezR commented 2 weeks ago

@civanch Okay, now it is more clear to me, thanks. I will push the changes here

cmsbuild commented 2 weeks ago

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-47165/43406

cmsbuild commented 2 weeks ago

Pull request #47165 was updated. @civanch, @cmsbuild, @kpedro88, @mdhildreth can you please check and sign again.

kpedro88 commented 2 weeks ago

please test

cmsbuild commented 2 weeks ago

+1

Size: This PR adds an extra 40KB to repository Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-85c747/43928/summary.html COMMIT: a952fa9db379040e0e92c79f19bb70bd254e940e CMSSW: CMSSW_15_0_X_2025-01-22-2300/el8_amd64_gcc12 User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/47165/43928/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

civanch commented 2 weeks ago

+1

@24LopezR , now it is needed to backport this PR to MC production releases 10_6_X (Run2), 12_4_X and 13_0_X (Run3). In the directory SimG4Core/Generators there is extra file Generator3.cc, which is a clone of the Generator class. This new class is a clone of the default one, we created it to use the new HepMC3 interface. If you agree, it is possible to copy modifications to Generator3.cc, this class does not exist in previous releases, so it is not needed to be backported.

cmsbuild commented 2 weeks ago

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)

24LopezR commented 2 weeks ago

@civanch okay thanks, I will prepare the backports. Regarding Generator3.cc, I agree, the same changes can be added there.

mandrenguyen commented 2 weeks ago

+1