Update to simplified ecal pfcluster corrections on top of new Global Tags for PF corrections plus fixes for Run2 MC production

[diguida]

Move to updated version of ecal pfcluster corrections with reduced number of input variables, plus some additional pt binning and slightly different parameterization to improve the behaviour at very low energies. Originally in #8818

New Global Tags including updated set of PF corrections for E-gamma and hadrons, and a couple of fixes for Run2 MC production. Originally in #8869

[cmsbuild]

A new Pull Request was created by @diguida (Salvatore Di Guida) for CMSSW_7_4_X.

Update to simplified ecal pfcluster corrections on top of new Global Tags for PF corrections plus fixes for Run2 MC production

It involves the following packages:

Configuration/AlCa
RecoParticleFlow/PFClusterProducer

@nclopezo, @cvuosalo, @cerminar, @cmsbuild, @diguida, @slava77, @mmusich can you please review it and eventually sign? Thanks.
@ghellwig, @Martin-Grunewald, @mmarionncern, @bachtis, @lgray this is something you requested to watch as well.
You can sign-off by replying to this message having '+1' in the first line of your reply.
You can reject by replying to this message having '-1' in the first line of your reply.
If you are a L2 or a release manager you can ask for tests by saying 'please test' in the first line of a comment.
@Degano you are the release manager for this.
You can merge this pull request by typing 'merge' in the first line of your comment.

[diguida]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.

[bendavid]

Yes, this looks right to me (therefore superseding #8818 )

[slava77]

it would have still been much easier to test and sign off if #8818 was updated (cherry-picking).
since all distributions change, it's easier to compare to the old run (to see no diffs); which is only meaningful in the same release; this PR starts from a different point in 74X history.
I will do this on my side.

Just to confirm: are the payloads in GT the same as the ones that were picked with esprefer?

[cmsbuild]

+1
Tested at: fb88a8f
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-8872/8515/summary.html

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_7_4_X IBs unless changes (tests are also fine). This pull request requires discussion in the ORP meeting before it's merged. @davidlange6, @Degano, @ktf, @smuzaffar

[slava77]

About #8872 (comment)
Based on my local tests with higher stats, I don't see the same big discrepancy in the plot for the wf 25202.

There are visible changes in flat-pthat dijet sample, which is more sane

I'd suspect something odd happening on the plotting side of the DQM that triggered that large change in #8872 (comment)

[slava77]

Some notes on the impact of GT changes (incrementally, on top of the ecal pfcluster correction changes)

PF hadron corrections are visible in expected places:

• 3 TeV dijet shows clear increase in response of neutral hadrons
  
  
  

jet response is much better (resolution is about the same)

the same sampled with dijet QCD

Castor response changes are visible:
noise component changes quite a lot (this is ele gun event, electrons don't point to castor)

the effects decrease with increased energy flow:
Flat-ptHat QCD sample (1338 workflow)

and even less in ttbar with PU35

[davidlange6]

+1

[diguida]

@slava77 Sorry, it seems that the reply I sent you via mail for #8872 (comment) did not land in the PR.
I confirm that the payloads in GT for PF E-gamma corrections are the same you have already tested in #8818 In addition to that, we have also made few more updates:

• improved set of PF hadron calibrations for all scenarios;
• fix of the L1 RCT parameters for Run2 simulations: they are now able to reproduce the behaviour of the L1T firmware
• fix of the Castor gains, in order to avoid saturation of the digis.

Your tests look consistent with the internal validation presented to AlCa and PPD.

Hope this clarifies