[16.0.X] switch off usePixelQualityFlag in TrackerTrackHitFilter in presence of the PixelCPEGeneric modifier

[mmusich]

backport of #50616

PR description:

This PR is a follow-up to #50480.
In that PR the default CPE for track fitting in the 2026 Era was moved to the CPE generic.
Unfortunately this has a knock-on effect on the TrackerTrackHitFilter which has a flag (usePixelQualityFlag) which relies on the template fit information to do hit rejection:

cmssw/RecoTracker/FinalTrackSelectors/plugins/TrackerTrackHitFilter.cc

Lines 976 to 997 in 0733146

	if (checkPXLQuality_) {
	const SiPixelRecHit *pixelhit = dynamic_cast<const SiPixelRecHit *>(therechit);
	if (pixelhit != nullptr) {
	//std::cout << "ClusterCharge=" <<std::flush<<pixelhit->cluster()->charge() << std::flush;
	float xyprob = pixelhit->clusterProbability(0); //x-y combined log_e probability of the pixel cluster
	//singl x- and y-prob not stored sicne CMSSW 3_9_0
	float xychargeprob = pixelhit->clusterProbability(1); //xy-prob * charge prob
	// float chargeprob =pixelhit->clusterProbability(2);//charge prob
	bool haspassed_tplreco = pixelhit->hasFilledProb(); //the cluster was associted to a template
	int qbin = pixelhit->qBin(); //R==meas_charge/pred_charge: Qbin=0 ->R>1.5 , =1->1<R<1.5 ,=2->0.85<R<1 ,
	// Qbin=3->0.95*Qminpred<R<0.85 ,=4->, =5->meas_charge<0.95*Qminpred
	// if(haspassed_tplreco) std::cout<<" CLUSTPROB=\t"<<xprob<<"\t"<<yprob<<"\t"<<combprob<<"\t"<<qbin<<std::endl;
	// else std::cout<<"CLUSTPROBNOTDEF=\t"<<xprob<<"\t"<<yprob<<"\t"<<combprob<<"\t"<<qbin<<std::endl;
	keepthishit = false;
	// std::cout<<"yyyyy "<<qbin<<" "<<xprob<<" "<<yprob<<std::endl;
	if (haspassed_tplreco && xyprob > pxlTPLProbXY_ && xychargeprob > pxlTPLProbXYQ_ && qbin > pxlTPLqBin_[0] &&
	qbin <= pxlTPLqBin_[1])
	keepthishit = true;
	} else {

This is of course not available when the template fit is not run.
This has lead to missing alignment PCL results (see e.g. https://cern.ch/wygsf) and potentially wrong DQM results.

PR validation:

I've re-run the following command (previously failing in CMSSW_16_0_4_patch2):

#!/bin/bash -ex

dasgoclient --limit 0 --query 'file dataset=/StreamExpress/Run2026C-TkAlMinBias-Express-v1/ALCARECO run=402536' | sort -u > input_files.txt
echo '{"402536": [[1, 116]]}' > step1_lumiRanges.txt

cmsDriver.py ReAlCaHLT \
  -s ALCA:PromptCalibProdSiPixelAli \
  --conditions 160X_dataRun3_Express_v1 \
  --scenario pp \
  --data \
  --era Run3_2026 \
  --datatier ALCARECO \
  --eventcontent ALCARECO \
  --process RECO \
  --processName ReAlCa \
  --filein filelist:input_files.txt \
  --lumiToProcess step1_lumiRanges.txt \
  -n 1000 >& ReAlCa.log

cmsDriver.py ALCAHARVDSIPIXELALI \
  -s ALCAHARVEST:SiPixelAli \
  --conditions 160X_dataRun3_Express_v1 \
  --scenario pp \
  --era Run3_2026 \
  --data \
  -n -1 \
  --filein file:PromptCalibProdSiPixelAli.root \
  --customise Alignment/CommonAlignmentProducer/customizeLSNumberFilterForRelVals.lowerHitsPerStructure >& Harvesting.log

and verfied the alignment PCL works correctly.

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:

Verbatim backport of #50616 to the 2026 data-taking release.

[cmsbuild]

A new Pull Request was created by @mmusich for CMSSW_16_0_X.

It involves the following packages:

• Alignment/CommonAlignmentProducer (alca)
• DPGAnalysis/SiStripTools (analysis)
• DQM/TrackingMonitorSource (dqm)
• RecoTracker/FinalTrackSelectors (reconstruction)

@Alejandro1400, @JanChyczynski, @Moanwar, @arunhep, @atpathak, @cmsbuild, @ctarricone, @gabrielmscampos, @jfernan2, @mandrenguyen, @nothingface0, @perrotta, @rseidita, @srimanob, @tvami can you please review it and eventually sign? Thanks.
@GiacomoSguazzoni, @VinInn, @VourMa, @arossi83, @dgulhan, @echabert, @elusian, @felicepantaleo, @fioriNTU, @gpetruc, @idebruyn, @jandrea, @mmasciov, @mmusich, @mtosi, @pakhotin, @richa2710, @robervalwalsh, @rovere, @rsreds, @sroychow, @threus, @tlampen, @tocheng, @venturia, @yuanchao 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 switch off usePixelQualityFlag in TrackerTrackHitFilter in presence of the PixelCPEGeneric modifier #50616

[cmsbuild]

cms-bot internal usage

[mmusich]

test parameters:

• workflows = 1000,1001,1001.2,1001.3,1001.4,1002.3,1002.4,1002.5

[mmusich]

@cmsbuild, please test

[cmsbuild]

+1

Size: This PR adds an extra 28KB to repository
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-82000f/52400/summary.html
COMMIT: 775d790
CMSSW: CMSSW_16_0_X_2026-04-01-1100/el8_amd64_gcc13
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/50619/52400/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• You potentially removed 4 lines from the logs
• Reco comparison results: 4 differences found in the comparisons
• DQMHistoTests: Total files compared: 61
• DQMHistoTests: Total histograms compared: 4531356
• DQMHistoTests: Total failures: 154
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 4531182
• DQMHistoTests: Total skipped: 20
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 60 files compared)
• Checked 264 log files, 213 edm output root files, 61 DQM output files
• TriggerResults: no differences found

[tvami]

+analysis

[arunhep]

+alca

[Moanwar]

+1

[rseidita]

+dqm

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_16_0_X IBs (tests are also fine) and once validation in the development release cycle CMSSW_16_1_X is complete. This pull request will now be reviewed by the release team before it's merged. @mandrenguyen, @sextonkennedy, @ftenchini (and backports should be raised in the release meeting by the corresponding L2)

[mandrenguyen]

+1