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RICH mirror alignment: optimize subset of mirror combinations and HLT1 selection criteria (RICH-62, RICH-16)

Anatoly Solomin requested to merge asolomin_OptimRichMirrAlignMST into master

To determine the RICH mirror misalignment compensations in the performance-wise optimal way, two key things are needed:

  1. best mirror combinations subset as a maximum spanning tree of the bipartite graph with primary and secondary mirrors as two disjoint and independent sets of its nodes and with amounts of mutually reflected photons as their edges' weights;

  2. for the HLT1 event selection line: precise solid angle selection windows for tracks that fill the photon"s delta theta vs. phi histograms for combinations from the above subset in the most efficient way.

This implements the determination of the above things.

The crucial question is whether selecting only events with at least one photon in at least one of the two most difficult to populatable mirror combinations of RICH2 '03s', '07p' (side 0) and '33p', '20s' (side 1) will automatically provide populating all the rest of the combinations with no fewer photons than for those two.

Checking of this is done under the option named "CheckRestFill" in RichSIMDAlignment.cpp and the conclusion is: the above selection is by far does not result in filling the rest of the combinations with no fewer photons than for those two. Therefore, that assumption proved wrong.

Edited by Anatoly Solomin

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