fixing Pythia6 Higgs mass parameters

[portalesHEP]

I realized that the Higgs mass parameter PMAS(25,1) was wrong in some of the wzp6 Higgs signal cards (due to some silly copy/pastes from my part, sorry about it). This may justify reproducing the samples affected. @EmanuelPerez @selvaggi FYI

[EmanuelPerez]

Salut Louis, thanks for spotting it. Actually, I am not 100% sure that changing PMAS is really needed : Whizard delivers to Pythia a Higgs with the correct (desired) mass value, and it could be that PMAS(25,1) is only used by Pythia in order to determine the maximum scale of the parton showers, for example - such that having 125 or 125.1 or whatever close-by value would not matter. But I have never checked that.. one would need to check that Pythia is not "rescaling" the Higgs before decaying it.. Maybe it is actually faster to just resubmit the jobs than to make the checks.. Or we could ask Jan to check one the samples, and look at the gen-level Higgs mass in the files.

[portalesHEP]

Just to be sure I looked at one of the samples in question (wzp6_ee_qqH_ecm240/events_192254938.root) and compared the gen Higgs mass to the invariant mass of its first two daughters, and it is indeed consistently 125 GeV. So, there does not seem to be a clear problem from having the wrong value for that parameter. Should I still merge this PR, or leave the cards as they are to keep the consistency with the generated samples?