Reshape RunI-like tracking customization snippet.

[rovere]

Back-port of #8691 into 74X. Could be extremely useful also for the 0T scenario.

[cmsbuild]

A new Pull Request was created by @rovere (Marco Rovere) for CMSSW_7_4_X.

Reshape RunI-like tracking customization snippet.

It involves the following packages:

RecoTracker/Configuration
RecoTracker/IterativeTracking

@cmsbuild, @cvuosalo, @nclopezo, @slava77 can you please review it and eventually sign? Thanks.
@ghellwig, @makortel, @GiacomoSguazzoni, @VinInn, @appeltel, @mschrode, @gpetruc, @cerati, @dgulhan, @venturia this is something you requested to watch as well.
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[slava77]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.

[slava77]

Hi Marco, just making a blind comparison of the number of lines, this PR doesn't match #8691
what are the changes?

[rovere]

@slava77 you are right, I might have missed 1 commit from #8691
I'll update this PR accordingly.
Thanks for noticing.

[slava77]

ah, ok, good that I checked.
At brief inspection, it looks like the changes in tracking parameters in the _iteration_cff are missing

[rovere]

Here they are.

[slava77]

summary for #9296 86fe202

• tested locally in CMSSW_7_4_3 /test area sign743b/
• the main test is based on run 200781 lumi=80 (~PU=30 with 0 T from 2012C) /store/data/Run2012C/MinimumBias/RAW/v1/000/200/781/7ED5DB39-DDE4-E111-9386-003048F118D2.root , using 1000.0 configuration otherwise. 100 events in the test.
• technical performance seems comparable: processing time up from 10.6 to 13.7 s/evt (peak moves from 29.4 to 35.8 s/evt), both excluding the first event dominated by conditions fetch.

Some object comparisons notes

• most tracks don't have MVA value assigned
  
• there are 50% more tracks (from the following distributions they appear to be "better" tracks)
  

• more electron gsf tracks as well
  
• but fewer PF egamma objects (more tracks probably kill some of them in the preselection)
  
• calo jets change a bit (likely due to the track->hbhe cleaning step)
  

PF reco is not quite trivial to understand (do we even know that it works OK?)

• about 30% less charged hadrons (opposite to 50% more tracks .. looks like PF RECO doesn't like these tracks.)
  
• similar decrease in electrons (this should follow what happens in the egamma objects; since the sample is mostly fakes, the meaning of decrease is unclear)
  
• muons are ~unchanged
• photons are ~unchanged
  
• ~15% more neutral hadrons
  

Overall, there are indications that tracking is indeed better, but higher level reco downstream (PF, specifically) maybe just not well adjusted to the 0T input track properties.
MC with truth matching would help to understand what's happening.

[slava77]

@bachtis Michalis, do you have any high expectations for PF reco with 0 T?
@lgray what about egamma?

[bachtis]

Hi Slava ,
I have discussed with PC . There are many ideas that are configurable and could be done at PF @0t
Examples:
[Run PF without tracks ~ 20% improvement for jet resolution wrt CaloJets]
Link tracks and Calo deposits and create PF candidates with Calo energy and track direction [and try to associate to PV]

Now the request from PC was to not invest in that direction for the high level reconstruction for now since we are looking at a middle term solution.
just for my education: @rovere @VinInn what is the pt of the tracks at 0 T and the error that you give?

[VinInn]

Seeds starts with 5GeV and some sort of large error.
than KalmanFilter is free to adjust most probably taking into account multiple-scattering...

[bachtis]

OK then PF will give random results since it assumes ~5 GeV track energy. Unless the error is very very large so that it will prefer the calo measurement. Ideal configuration for PF to run out of the box would be : track pt = 0.0 +- 100 TeV

[slava77]

+1

for #9296 86fe202

• the new configuration can be enabled with --customise RecoTracker/Configuration/customiseForRunI.customiseForRunI
• some performance notes were posted earlier in the thread

[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, @smuzaffar

[davidlange6]

+1