Reject 0 pt Puppi candidates in jet-track association

[ferencek]

Charged PF candidates identified by the Puppi algorithm as pileup have their momenta scaled to 0. Consequently, eta and phi of such candidates are reset to 0 which can lead to spurious association of these candidates to jets whose axes point in the vicinity of (eta,phi)=(0,0). To reject such spurious associations, the candidate momentum is required to be greater than 0.

This change is completely transparent to all existing b-tagging algorithms and all monitored quantities. It manifests itself only in non-default setups where Puppi candidates are set as input for b tagging.

[cmsbuild]

A new Pull Request was created by @ferencek (Dinko Ferencek) for CMSSW_9_0_X.

It involves the following packages:

RecoBTag/ImpactParameter

@cmsbuild, @cvuosalo, @slava77, @davidlange6 can you please review it and eventually sign? Thanks.
@imarches, @acaudron, @JyothsnaKomaragiri, @mverzett, @ferencek, @pvmulder this is something you requested to watch as well.
@davidlange6, @smuzaffar you are the release manager for this.

cms-bot commands are listed here #13028

[slava77]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/17958/console Started: 2017/02/24 23:49

[cmsbuild]

+1
Tested at: 1866067
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-17626/17958/summary.html

[cmsbuild]

Comparison job queued.

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-17626/17958/summary.html

[slava77]

given backport to 80X, I think it's worth keeping this in 90X as well

[slava77]

+1

for #17626 1866067

• analysis-only change (in the current default workflows context); implemented as described
• jenkins tests pass and comparisons confirm there are no differences

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_9_0_X IBs (tests are also fine). This pull request requires discussion in the ORP meeting before it's merged. @davidlange6, @smuzaffar

[davidlange6]

+1