Filter infinite loops in muon trajectory reconstruction [15_0_X]

[BlancoFS]

PR description:

Backport of #48318

This PR is supposed to fix the issue introduced in CMSHLT-3557. After some investigations, it was observed that a determined sequence of measurements led to an infinite loop in the muon OI trajectory reconstruction. In particular, a pair of valid and invalid (with detId=0) hits was continuously added to the trajectory.

To solve that, the toBeContinued function is modified for the BaseCkfTrajectoryBuilder class. There, if the number of measurements is sufficiently large the last hit, the last to last hit, and the last to last to last hit are checked. If the current hit is equal to the last-2, and the last hit is equal to the last-3; then that temporal trajectory is not continued.

PR validation:

First, the PR is confirmed to successfully solve the issue in CMSHLT-3557. Secondly, it was checked that no other seed from that run fired the logic. A third validation is ongoing to confirm that there is no physics difference.

[cmsbuild]

A new Pull Request was created by @BlancoFS for CMSSW_15_0_X.

It involves the following packages:

• RecoTracker/CkfPattern (reconstruction)

@cmsbuild, @jfernan2, @mandrenguyen can you please review it and eventually sign? Thanks.
@GiacomoSguazzoni, @VinInn, @VourMa, @dgulhan, @felicepantaleo, @gpetruc, @missirol, @mmusich, @mtosi, @rovere 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

• Backported from Filter infinite loops in muon trajectory reconstruction [CMSHLT-3557] #48318

[cmsbuild]

cms-bot internal usage

[Martin-Grunewald]

please test

[mmusich]

backport of #48318

[cmsbuild]

+1

Size: This PR adds an extra 20KB to repository
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-edb105/46807/summary.html
COMMIT: d6ff145
CMSSW: CMSSW_15_0_X_2025-06-17-2300/el8_amd64_gcc12
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmssw/48351/46807/install.sh to create a dev area with all the needed externals and cmssw changes.

The following merge commits were also included on top of IB + this PR after doing git cms-merge-topic:

• @perrotta Update 150X GTs as of 13/06/2025 in autoCond - [CMSSW_15_0_X] #48322

You can see more details here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-edb105/46807/git-recent-commits.json
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-edb105/46807/git-merge-result

Comparison Summary

Summary:

• You potentially added 5 lines to the logs
• ROOTFileChecks: Some differences in event products or their sizes found
• Reco comparison results: 7673 differences found in the comparisons
• DQMHistoTests: Total files compared: 51
• DQMHistoTests: Total histograms compared: 4121776
• DQMHistoTests: Total failures: 169300
• DQMHistoTests: Total nulls: 2
• DQMHistoTests: Total successes: 3952454
• DQMHistoTests: Total skipped: 20
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: -224.30700000000002 KiB( 50 files compared)
• DQMHistoSizes: changed ( 16834.0,... ): -112.246 KiB GEM/Digis
• DQMHistoSizes: changed ( 16834.0,... ): -1.978 KiB GEM/RecHits
• DQMHistoSizes: changed ( 17034.0 ): 4.141 KiB SiStrip/MechanicalView
• Checked 222 log files, 194 edm output root files, 51 DQM output files
• TriggerResults: found differences in 9 / 49 workflows

[jfernan2]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_15_0_X IBs (tests are also fine) and once validation in the development release cycle CMSSW_15_1_X is complete. This pull request will now be reviewed by the release team before it's merged. @sextonkennedy, @antoniovilela, @rappoccio, @mandrenguyen (and backports should be raised in the release meeting by the corresponding L2)

[mandrenguyen]

+1