Pass fraction for intrinsic nue to HSN trigger (NECESSARY FOR UNBLINDING)

The purpose of the analysis is to determine how many intrinsic nue events would pass the trigger selection.
This is necessary for getting permission to unblind data. The official criteria for unblinding is:

"The filter must NOT select more than 45 electron neutrino charged current interactions in an energy range from 50 MeV to 1.5 GeV in 6.6E20 POT of data." (DocDB 7073)

The definition used for analysis will be:


The samples with no cosmics would actually be better, but they are not available in MCC8.4. However the cosmic overlay in the nue samples should not alter the timing distributions. Which means that nue and nue_cosmics should be inetrchangeable for this analysis.

Three triggers will be used:

Standard BNB trigger window [BNB_FEMBeamTriggerAlg]
Standard HSN trigger window [BNB_HSN_c0_FEMBeamTriggerAlgo]
"Short" HSN trigger window [BNB_HSN_short_c0_FEMBeamTriggerAlgo]

The "short" HSN trigger window, is a limited window situated after the BNB window, which does not include the BNB window. Its length is basically the difference of (HSN time range) - (BNB time range).

Based on this plot, and assuming the HSN trigger is doing its job:

That means the intrinsic nue pass fraction is 6e-4. We need now to know the number of intrinsic nue in 6e20 POT.