Update the default input for rho in the jet energy corrections in PAT in 5_3_X

[TaiSakuma]

This PR addresses the issue #6530.

[cmsbuild]

A new Pull Request was created by @TaiSakuma (Tai Sakuma) for CMSSW_5_3_X.

Update the default input for rho in the jet energy corrections in PAT in 5_3_X

It involves the following packages:

PhysicsTools/PatAlgos

@cmsbuild, @vadler, @nclopezo, @monttj can you please review it and eventually sign? Thanks.
@mmarionncern, @imarches, @acaudron, @nhanvtran, @schoef, @ferencek, @mariadalfonso, @pvmulder this is something you requested to watch as well.
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[vadler]

Tests ongoing with CMSSW_5_3_X_2014-11-20-1400. The differences in jet pt shown below are expected, but also b-tag discriminators show mild effects (one example shown).

[vadler]

-1
@TaiSakuma : Unfortunately, it is not enough just to switch the default configuration, since it is potentially modified later. The classes AddJetCollection, SwitchJetCollection and SwitchJetCorrLevels in PhysicsTools/PatAlgos/python/tools/jetTools.py need to be adapted, too, using the existing jetType-variable to determine the correct name of the input rho.

[TaiSakuma]

@vadler, I see. Thank you for looking into it. I will see if I can properly update.

[ferencek]

Since in the PAT workflow b tagging is applied to uncorrected jets, the only way (other than numerical instability) I can explain differences in the b tag discriminators is if there is a jet selection cut applied so that updated JEC's cause some jets to migrate either inside or outside the selection region.

[cmsbuild]

+1
Tested at: 856b4fd
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-6561/1140/summary.html

[cmsbuild]

-1

Tested at: 0a176e2
I found errors in the following unit tests:

---> test runtestPhysicsToolsPatAlgos had ERRORS

you can see the results of the tests here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-6561/6796/summary.html

[monttj]

Apart from this test failure,
I guess the scale factor for this rho correction (jet and isolation) provided by POG is based on "kt6PFJets" for Run 1. And we ended up with using PFJets for most of analyzers. So we changed the default jets to PFJets at some point in 7X in PAT.

So I think this PR should be the other way around.
Instead of changing the rho to Calo, we could change the default jets to ak5PFJets in 53X.

Taejeong

[TaiSakuma]

I looked at the test error. The error is not caused by a commit in this PR. The error occurred because the Xrd connection failed.

[TaiSakuma]

@monttj, It is true that most of the analyses use PFJets and the default is PFJets in 7XX. However, I am not sure if it is really a good idea to change the default for 53X at this point. It would be quite a big change. 530 was released three years ago. The default has been the CaloJets in 53X. 53X is approaching the end of its lifetime. I think that the default for 53X should stay CaloJets. Also in 53X, patDefaultSequence doesn't fully use PF objects. I don't think that the default sequence will be a sensible default if the jets are changed to PF jets unless other objects will also be switched to PF objects.

At the moment, the default gives src = "ak5CaloJets" and rho = 'kt6PFJets". This combination is wrong.

This PR is to give a sensible default combination by correcting the default choice of rho.

[monttj]

+1
Okay, analyzers should have their own PAT sequence in 53X for PFJets anyway.

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_5_3_X IBs unless changes (but tests are reportedly failing). This pull request requires discussion in the ORP meeting before it's merged. @davidlange6, @smuzaffar, @ktf

[TaiSakuma]

is this going to be merged someday?