Hi,
I updated the page
http://www.slac.stanford.edu/~daniele/vub/theoscan.html
and I added the plots for the pstar cut scan. They are the four last
tables of the page with
- hybrid model
- non res model
- non res mb = 4.65
- non res a = 3.1
No striking effect here.
Daniele
On Sun, 24 Nov 2002, Daniele del Re wrote:
>
> Hi all,
>
> I studied a bit more in detail the problem of the instability
> of the result as a function of the hadronic mass cut.
>
> As you know, our biggest systematics is the theoretical one
> and it is very dependent on the Mx cut itself.
> This implies that it can introduce a slope in the Mx scan.
>
> I tried to reweight the MC model shifting the theoretical parameters
> mb and a in order to check the impact on this scan. The hope
> is that the scan is just telling us that mb and a are not the ones
> in the MC model.
>
> In
>
> http://www.slac.stanford.edu/~daniele/vub/theoscan.html
>
> you find the scans in many configurations.
>
> The first five tables show the data for the following configurations:
>
> - default
> - mb = 4.65 (-0.15) , a = 1.290 (default)
> - mb = 4.95 (+0.15) , a = 1.290 (default)
> - mb = 4.60 (-0.20) , a = 1.290 (default)
> - mb = 4.80 (default) , a = 3.1 (+2.31)
> - mb = 4.80 (default) , a = 0.91 (-0;19)
>
> As you can notice, moving mb down and a up, fixs part of the discrepancy
> at low Mx low values.
>
>
> As a crosscheck, I verified the impact on the generic MC, that is shown
> in the second set of tables.
> (in order to reproduce the effect on data, you should imagine to flip the
> slopes and the shifts since here I am reweighting the model not the
> fitted sample)
>
>
> My comments:
>
> 1) moving the theoretical paramenters (down mb and up a, but in
> particular a) recovers part of the problem at low Mx.
>
> 2) generic MC is able to reproduce the effect at low Mx.
>
> 3) generic MC shows that the B0s are more sensitive to this systematics.
> Probably this is due to the slightly better S/B??
>
> 4) our measurement is so clean and we have so many events that we are
> sensitive to these theoretical parameters. We can start thinking about
> fitting a and mb.
>
> 5) I am a bit less worried about this slope now
>
>
> Daniele
>
>
>
>
>
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