[16_1_X][L1T] EMTF DQM Plot Changes to Address CSC Timing Issues for Backport

[kmorrison314]

PR description:

The proposed changes effect the cscLCTTiming Plots in the EMTF DQM and work to address poor resolution seen in the CSC chambers in the negative endcap, documented here.

An EMTF investigation revealed that EMTF tracks built with more than or equal to 2 RPC hits contributed significantly to the csc chamber occupancy in BX -1 for the negative endcap region which is not mirrored in the positive endcap region. The source of this problem is a known retriggering issue in RPC chambers in negative endcap. The fix implemented in the PR is to remove tracks with more than or equal to 2 RPC hits from the cscLCTTiming monitoring plots which are used to extract CSC Timing shifts

PR validation:

n order to validate this reason, the BX-1 csc chamber occupancy was plotted for tracks with more than or equal to 2 RPC hits and showed that the occupancy only existed in the negative endcap for a total of 100,000 events (See image below).

To further validate the fix, the DQM was run over 153,000 events and included cscLCTTiming plots with and without the 2 RPC hit tracks. Through this it is shown that there is an improvement in the csc chamber occupancy in BX-1 and thus the timing resolution (See below).

Before Fix

After Fix

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:

The original PR can be found #50903. This is a backport request for CMSSW_16_1_X as this affects online DQM.

[cmsbuild]

A new Pull Request was created by @kmorrison314 for CMSSW_16_1_X.

It involves the following packages:

• DQM/L1TMonitor (dqm)

@cmsbuild, @ctarricone, @gabrielmscampos, @nothingface0, @rseidita can you please review it and eventually sign? Thanks.
@missirol, @mmusich this is something you requested to watch as well.
@ftenchini, @mandrenguyen, @sextonkennedy you are the release manager for this.

cms-bot commands are listed here

• Backported from [L1T] EMTF DQM Plot Changes to Address CSC Timing Issues #50903

[cmsbuild]

cms-bot internal usage

[gabrielmscampos]

backport of #50903

[gabrielmscampos]

test parameters:

• addpkg = DQM/Integration

[gabrielmscampos]

please test

[cmsbuild]

+1

Size: This PR adds an extra 20KB to repository
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-9ac323/53205/summary.html
COMMIT: 7e5db44
CMSSW: CMSSW_16_1_X_2026-05-12-1100/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/50921/53205/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• You potentially added 2 lines to the logs
• Reco comparison results: 17 differences found in the comparisons
• DQMHistoTests: Total files compared: 53
• DQMHistoTests: Total histograms compared: 4182125
• DQMHistoTests: Total failures: 78
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 4182027
• DQMHistoTests: Total skipped: 20
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 52 files compared)
• Checked 227 log files, 197 edm output root files, 53 DQM output files
• TriggerResults: no differences found

[gabrielmscampos]

+dqm

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_16_1_X IBs (tests are also fine) and once validation in the development release cycle CMSSW_17_0_X is complete. This pull request will now be reviewed by the release team before it's merged. @ftenchini, @mandrenguyen, @sextonkennedy (and backports should be raised in the release meeting by the corresponding L2)