Normalisation of Powheg MiNNLO samples
The MiNNLO sample used for Z->µµɣ contain events with very large weights (up to \mathcal O(10^{19})). Most events have a weight of \pm 2374, which is close to the total cross section for Z->µµ. The outliers don't seem to survive the selection.
When normalizing the sample, the sum of the weights is dominated by a couple of outliers that generally don't even have gen-level muons:
root [1] inclusive_jets->Scan("event.genWgts.v:genMuons.p4.fPt:genMuons.p4.fEta", "event.@genWgts.at(0).v > 10000000")
***********************************************************
* Row * Instance * event.gen * genMuons. * genMuons. *
***********************************************************
* 9790914 * 0 * 4.561e+19 * * *
* 10346647 * 0 * 7.484e+17 * * *
* 10723883 * 0 * 1.833e+19 * * *
* 18105160 * 0 * 1.918e+16 * * *
* 32640902 * 0 * 1.632e+17 * 27.850315 * -2.108075 *
* 51271134 * 0 * 1.895e+16 * * *
* 70568346 * 0 * 7.591e+17 * * *
***********************************************************
==> 7 selected entries
(long long) 7These weights don't look physical:
