[Halld-offline] [EXTERNAL] Accidental scaling factors in DSelectors

[Sean Dobbs]

Hi all,

To make it easier to evaluate the effect (if any) of the accidental
scaling factors on physics results (e.g. cross sections), I recently
added the factors that Beni extracted into the CCDB.

If you use the latest version of the ROOT analysis software, you can
obtain the scaling factors and their associated uncertainties using
code like the following:

double scaling_factor =
dAnalysisUtilities.Get_AccidentalScalingFactor(locRunNumber,
locPhotonBeamEnergy);
double scaling_factor_err = dAnalysisUtilities.
Get_AccidentalScalingFactorError(locRunNumber, locPhotonBeamEnergy);

This scaling factor is used as a multiplicative factor for accidental
subtraction.

Please let me know if you have any questions about this, and it would
be good to hear about the effects of applying these factors on cross
section measurements at some future Production & Analysis Meeting.

Cheers,
Sean