Fix jet energy fractions after jet resolution smearing

[ahinzmann]

PR description:

As currently implemented, jet resolution smearing breaks the jet energy fraction variables of pat::Jets.
This line of code changes the four-vector of a pat::Jet, but not the correction factors stored in the pat::Jet:
https://github.com/cms-sw/cmssw/blob/CMSSW_8_0_25/PhysicsTools/PatUtils/interface/SmearedJetProducerT.h#L267
Jet energy fraction calculation relies on the fact that one can retried the raw jet energy with the stored correction factors:
https://github.com/cms-sw/cmssw/blob/master/DataFormats/PatCandidates/interface/Jet.h#L376

This fix to the scaleEnergy method adjusts the stored correction factors, to be able to retrieve the raw jet energy again.

Jet resolution smearing is run during MiniAOD production and also in this test:
https://github.com/cms-sw/cmssw/blob/master/PhysicsTools/PatAlgos/test/corMETFromMiniAOD.py

Small changes are expected in MET corrections and uncertainties related to jet resolution smearing in MiniAOD.

PR validation:

It was checked that jet energy fractions are the same before and after jet energy resolution smearing with this fix.

[cmsbuild]

The code-checks are being triggered in jenkins.

[cmsbuild]

The code-checks are being triggered in jenkins.

[cmsbuild]

-code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-27428/10727

• This PR adds an extra 28KB to repository

Code check has found code style and quality issues which could be resolved by applying following patch(s)

• code-format:
  https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-27428/10727/code-format.patch
  e.g. curl https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-27428/10727/code-format.patch | patch -p1
  You can also run scram build code-format to apply code format directly

[cmsbuild]

The code-checks are being triggered in jenkins.

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-27428/10728

• This PR adds an extra 28KB to repository

[cmsbuild]

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

It involves the following packages:

DataFormats/PatCandidates

@perrotta, @cmsbuild, @santocch, @slava77 can you please review it and eventually sign? Thanks.
@gouskos, @hatakeyamak, @rovere, @cbernet, @gpetruc, @peruzzim this is something you requested to watch as well.
@davidlange6, @slava77, @fabiocos you are the release manager for this.

cms-bot commands are listed here

[cmsbuild]

The code-checks are being triggered in jenkins.

[ahinzmann]

In addition to the original problem, this solution also stores the smearing factor for bookkeeping in pat::Jets that contain JECs.

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-27428/10740

• This PR adds an extra 32KB to repository

[slava77]

What's the best strategy, to have analyzers use this bug-fix at least in analysis code in 10_2?

The best strategy will have to adhere to the no-change policy (the code running in production should not change physics results).
I'm not sure how this can be done in the context of coding in this PR.
For a backport there better be a config parameter to switch the behavior.

[cmsbuild]

+1
Tested at: 56e606d
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-1786a3/1441/summary.html

[cmsbuild]

Comparison job queued.

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-1786a3/1441/summary.html

Comparison Summary:

• No significant changes to the logs found
• Reco comparison results: 77 differences found in the comparisons
• DQMHistoTests: Total files compared: 32
• DQMHistoTests: Total histograms compared: 3081858
• DQMHistoTests: Total failures: 1
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 3081535
• DQMHistoTests: Total skipped: 322
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 31 files compared)
• Checked 133 log files, 14 edm output root files, 32 DQM output files

[slava77]

What's the best strategy, to have analyzers use this bug-fix at least in analysis code in 10_2?

Is this particularly important for 10_2_X?

[slava77]

+1

for #27428 56e606d

• code changes are in line with the PR description and the follow up review. Changes are expected only in miniAOD MC workflows in smeared MET uncertainties/corrections
• jenkins tests pass and comparisons with the baseline show differences only in 2017,2018 and phase-2 MC in the smeared MET uncertainties/corrections. The differences are typically only on single events (out of 10 tested, as in most of the workflows with MC); so, the other MCs are apparently just lucky to have no diff.

[fabiocos]

@santocch could you please review this PR?

@ahinzmann for backports we need to be careful in not changing the existing miniAOD default behaviour, as @slava77 says

[slava77]

@ahinzmann for backports we need to be careful in not changing the existing miniAOD default behaviour, as @slava77 says

I think that for 10_6_X we should still be OK as is. Not for 10_2_X.

[fabiocos]

+1

[fabiocos]

merge

[santocch]

+1

[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 will be automatically merged.