Modification of Pixel Pair Step in HI Tracking

[abaty]

After the inclusion of additional quadruplet iterations for Phase 1 tracking in PR #18646, we have decided to mostly remove the pixel pair step from the phase 1 HI tracking workflow (similar to what was done for pp tracking). Studies here show that this iteration is only recovering 1-2% efficiency, while also contributing ~1% fake rate. A small tracking region for pixel layers 1 and 4, and forward pixel disk 1 has been kept to cover a gap in acceptance of BPIX2 and 3 (very similar to this pp PR: #19051).

Timing studies show an overall decrease in tracking time in 0-10% events from ~109 s to ~99 s, and from 10.3 to 9.7s in inclusive events.

Testing can be done using the HI Phase 1 relval proposed in PR #19089.
@mandrenguyen

[cmsbuild]

A new Pull Request was created by @abaty for master.

It involves the following packages:

RecoHI/HiTracking

@perrotta, @cmsbuild, @slava77, @davidlange6 can you please review it and eventually sign? Thanks.
@jazzitup, @echapon, @yenjie, @kurtejung, @mandrenguyen, @dgulhan, @yetkinyilmaz this is something you requested to watch as well.
@davidlange6 you are the release manager for this.

cms-bot commands are listed here

[perrotta]

please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/21001/console Started: 2017/06/29 17:54

[cmsbuild]

+1
Tested at: 6738825
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-19486/21001/summary.html

The following merge commits were also included on top of IB + this PR after doing git cms-merge-topic:
1974578
You can see more details here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-19486/21001/git-log-recent-commits
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-19486/21001/git-merge-result

[cmsbuild]

Comparison job queued.

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-19486/21001/summary.html

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

• /build/cmsbld/jenkins-workarea/workspace/compare-root-files-short-matrix/results/JR-comparison/PR-19486/20034.0_TTbar_14TeV+TTbar_14TeV_TuneCUETP8M1_2023D17_GenSimHLBeamSpotFull14+DigiFullTrigger_2023D17+RecoFullGlobal_2023D17+HARVESTFullGlobal_2023D17
• /build/cmsbld/jenkins-workarea/workspace/compare-root-files-short-matrix/results/JR-comparison/PR-19486/20434.0_TTbar_14TeV+TTbar_14TeV_TuneCUETP8M1_2023D19_GenSimHLBeamSpotFull14+DigiFullTrigger_2023D19+RecoFullGlobal_2023D19+HARVESTFullGlobal_2023D19

Comparison Summary:

• No significant changes to the logs found
• Reco comparison results: 0 differences found in the comparisons
• DQMHistoTests: Total files compared: 22
• DQMHistoTests: Total histograms compared: 1756063
• DQMHistoTests: Total failures: 14510
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 1741387
• DQMHistoTests: Total skipped: 166
• DQMHistoTests: Total Missing objects: 0
• Checked 90 log files, 14 edm output root files, 22 DQM output files

[perrotta]

• Configuration changes for hiPixelPairStep: mostly removing pixel pair step from HI tracking in Phase 1
• As stated in the description, it leads to an overall reduction of the HI tracking time.
• Tested running with the newly defined workflows 150,, 150.1, 150.2, 150.3
• Performance of the modified HI tracking was studied by the proponents and summarized in the PR description

[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 requires discussion in the ORP meeting before it's merged. @davidlange6, @smuzaffar

[perrotta]

I removed the "+1" from the comment above, not because I found anything wrong with this PR, but because I would like to see some of those performance plots (eff, fakerates, ...) you summarizes in the PR description.

Could you please provide a link to a presentation in which you showed those performances, or just attach some distribution here? Then "+1" will follow.

[abaty]

@perrotta
A study of the efficiency and fake rate from this iteration can be found on slide 4,5 here.
Justification for the regional tracking around the hole in BPIX2+3, as well as timing numbers can be found here.

[perrotta]

Thank you @abaty

As far as I understand, in https://indico.cern.ch/event/646309/contributions/2625076/attachments/1475706/2285895/PixelPairStudy.pdf you have the efficiency (and fake-rates) for including the pixelPairStep everywhere.

Since in this PR you only apply it in a eta/phi slice, do you have the same plots with the same config as in this PR? Page 6 in https://indico.cern.ch/event/649262/contributions/2639830/attachments/1483753/2302322/Baty_PixelPairUpdate_TrackingMeeting.pdf makes me confident that the efficiency is correctly recovered where needed, but it would be nice to have here also plots with the actual setup proposed here.

[abaty]

@perrotta

You can find the efficiency and fake rates for the code in this PR (i.e. only the regional pair step) here. The extra tracks found by the pair step are shown by the dark brown contributions to the histogram.

[perrotta]

+1

• Configuration changes for hiPixelPairStep: it removes pixel pair step from HI tracking in Phase 1 everywhere but in a slice needed to recover efficiency for holes in BPix2+3 layers
• As stated in the description, it leads to an overall reduction of the HI tracking time with respect to the usage of PixelPairStep everywhere; about 4 to 9% of that reduction (depending on centrality) is given back when the pixelPairStep is only used in the slice
• Tested running with the newly defined workflows 150,, 150.1, 150.2, 150.3
• Performance of the modified HI tracking was studied by the proponents and summarized in the PR description, and in Modification of Pixel Pair Step in HI Tracking #19486 (comment)

[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 requires discussion in the ORP meeting before it's merged. @davidlange6, @smuzaffar

[davidlange6]

+1