Well, at least you got it!  (-:

On Fri, 17 May 2002, Riccardo Faccini wrote:

> Hi Oliver
> [incidentally I realized that your mails never get to vub-recoil because
> you send files in attachment and they get rejected. In order to circulate
> a plot to vub-recoil you need to send a web address]
>
> >
> >
> > lets settle this cfit case and concentrate on the
> > "DATA vs MC" and "MCcock vs MCgen" comparison.
> >
> > > > I am not sure that I understand your statement that the cocktail mc
> > > > has a better resolution than the generic MC. Attached to this mail
> > > > you will find a comparison of the Mx resolution obtained from cocktail
> > > > and generic for sp4run2 MC. After a 1bin (!) sideband subtraction they
> > > > seem to be pretty much identical. Are I am missing something?
> > > > By the way, the plot are made with 0.5 GeV missing mass cut and
> > > > P*>1.0 GeV. It should match the cuts used for the Vub stuff.
> > >
> > > I am sorry but I disagree on the fact that the two plots are identical:
> > > the generic is clearly biassed on the high side wrt to the cocktail and
> > > maybe also the resolution is slightly different
> > >       ciao
> > >       ric
> > >
> > >
> >
> > The discrepancy between ~-1.0 and ~-0.25 GeV you are
> > referring to is just an artifact of my sideband
> > isubtraction. As pointed out in my previous mail
> > I only use one bin in Mx in order to carry out
> > this subtraction.
> > The negative region of Mx(true) - Mx(reco)
> > corresponds to "high Mx(reco)" values where
> > we expect to have the largest contribution from
> > the sideband background. Therefore, the sideband
> > subtraction in our analysis is always performed in
> > bins of Mx in order to account for this correlation.
> > I have attached a plot showing the same Mx(true)-Mx(reco)
> > distribution but this time the sideband subtraction
> > is only performed between -1.5 and 0 GeV. This already
> > reduces the discrepancy between "MCcock vs MCgen"
> > a lot demonstrating that it is just an artifact
> > rather that a real effect. In our Mx moment
> > analysis we are using 5 Mx bins for the high mass
> > region in order to make this sideband subtraction.
> > If you want I can send you the plots - they clearly show
> > that the cocktail MC and the generic MC are leading
> > to very similar (identical within errors)
> >  resolutions and shapes for MX.
> >
> > I guess  "MCcock vs MCgen" is also something
> > we can settle now and move forward to our biggest
> > problem the "DATA vs MC" discrepancy (don't you agree?!)
>
> The plots you and daniele show go in the direction that here is an effect,
> but I agree that there are bigger ones. I am trying to get the
> required smearing to apply to the Breco in coctail in order to reproduce
> the generic. If this were enough to remove the discrepancies I this we
> would have taken one degree of confusion out of the discussion
> 	ciao
> 	ric
>
>