> Hi Daniele,
> this is not what shown in our Vub conf papers where the purity of the mes
> plots is by eye almost a factor 2 worse than BAD976.
>
> Do you agree?
well, if I compare
http://www.slac.stanford.edu/babar-internal/BAD/doc/download.html?file=01255.016.ps
pag 12
with
http://www.slac.stanford.edu/babar-internal/BAD/doc/download.html?file=00976.014.ps
pag 14
I see a large difference in the background shape but if you look at the
signal region S/B is not so different (20/30% worse?)
But I agree that it is worse and this is due to the different mode
composition in the final sample.
By using the tables I sent in my posting it should be possible to track
which is the mode that is causing the difference.
Daniele
> ciao
> ric
>
> ______________________________________________________
> Riccardo Faccini
> BaBar Physics Analysis Coordinator
>
> SLAC | Universita' "La Sapienza" & I.N.F.N. Roma
> tel +1/650/9265287 | tel +39/06/49914798
> cell+1/650/3925585 |
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> web page : http://www.slac.stanford.edu/~rfaccini
>
>
> On Wed, 26 Oct 2005, Daniele del Re wrote:
>
> >
> > Hir Henning,
> >
> > > I have a question concerning the change of Breco purity when moving from
> > > SP4/rel.10 (most of the run1-2 analyses) to SP6/rel.14 (run1-4).
> > >
> > > Do you see a reduction in purity with the newer reconstruction release in
> > > both data and MC?
> > > And can you possibly quantify it?
> >
> > the purity with no DE cut should be improved since the skim rate went from
> > 4% to 1.5% on data. Once you apply the mode dependent deltaE cut you
> > should get a similar purity compared to rel 10 (probably slightly worse).
> > Which machinery are you using to produce ntuples and to select the best B?
> >
> > > Similarily for the yield, I guess this is higher per fb-1 for the new
> > > release but does someone have some numbers?
> >
> > there should be an increase of around 15-20%.
> >
> > > I expect you only have these numbers for events with an identified lepton
> > > and not for all Breco candidates, but this would already help.
> >
> > for a per mode comparison (no cut) you can compare the tables in
> >
> > http://www.slac.stanford.edu/~daniele/breco/temp/sxModes-{2,3,4,5}.html
> > for run1-4 rel14
> > with
> > http://www.slac.stanford.edu/BFROOT/www/Physics/Analysis/AWG/InclusiveSL/islrecoil/data0909_80fb-1/sxModes-{2,3,4,5}.html
> > for 80 fb-1 rel10
> >
> > > For the Breco b->sg analysis we see a higher (BB) background i.e. reduced
> > > purity and would like to better understand this.
> >
> > the lower purity can be due to just few new modes that were not present in
> > rel 10 (because of the new tables). If they bother a lot you can identify
> > them and cut them out.
> >
> > Daniele
> >
>
