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Hi Urs, my approach has been to make sure that the Ks bug removed and the no ks bug removed MC look the same as far as rate and spectra are concerned. I was expecting to make a rescaling, but when I did the comparison, I found out that a killing is enough. The reaction of the neutral group has been that we should just throw away that MC. Once we have the full sample of generic we will be able to do so, so I would keep this fix that works (Fabio confirmed it in b->s gamma) waiting for the generic to be fully processed. ciao ric On Thu, 24 Oct 2002, Urs Langenegger wrote: > > Hoi Ric, > > discussions with Denis and Alessio have not solved my confusion about > your killing function. > > I peeked into the gam lists and generator blocks of events with > K0s->pi0pi0 in the old MC. The wrong bumps do not have a truth-match > by virtue of the bug (I seem to remember this, and I have not found a > single counter example). So either they are merged with the correct > bump or we will never kill the proper one with the current setup. > > If the bad photons are merged with the correct one (this can be > checked from the kinematics of the decay modulo resolutions since the > correct photons have the link back to the mothers), killing is -- on > an event by event basis -- not the right thing to do. Rescaling the > energy would seem more appropriate. > > If they are not merged and the bad photons are still in the event, we > should be able to find the best match to the K0S decay from the > unmatched photons and throw out the correct ones. This amounts to the > same as what is done in VubRemoveOrphans. I guess it would be good to > understand why VubRemoveOrphans fails to remove them properly. > > Cheers, > --U. > >