Fix bug chosing closest simHit

[wmtford]

This fixes a bug in SiPixelRecHitsValid noticed by Danek. It's in the logic that chooses the best simHit among those that match a recHit. It is relevant for only about 10% of recHits. The effect is undetectable in the matching residual plots with 500 3-TeV-jet events (no PU). I made a test filling the histograms only for the recHits with multiple simHits, and find that fixing the bug makes some improvement in some of the residual plots.

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[cmsbuild]

A new Pull Request was created by @wmtford for CMSSW_7_4_X.

Fix bug chosing closest simHit

It involves the following packages:

Validation/TrackerRecHits

@cmsbuild, @danduggan, @nclopezo, @deguio can you please review it and eventually sign? Thanks.
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[ghost]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.

[deguio]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_7_4_X IBs unless changes or unless it breaks tests.

[cmsbuild]

+1
Tested at: c214000
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-7362/2110/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 will be automatically merged.

[cmsbuild]

+1
Tested at: c214000
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-7362/2116/summary.html