Use of sigma(VPDL) in prediction histogram

Last Update: 31-May-05

Problem with the use of the VPDL error in predicted histograms. This error depends on the source (through M) and is correlated with Pt(meas).

σ(vpdl) = σ(L) * M / Pt(meas)

In the current (v3.1) code, an average value of σ(vpdl) is used when creating predicted histograms. The effects of this can be seen when comparing the generated (black) vs predicted (red) VPDL distributions for one of the sources.

Cannot simply use random sampling of σ(vpdl) histogram (from event generation) when creating prediction histogram because of correlation between σ(vpdl) and Pt(meas).