Hi,
I won't be able to attend tomorrow's meeting due to a concurrent
practice talk session which I am organizing. Here is an update on the
partial branching fraction measurement from mx-q2:
1) by using the new reweighting files provided by Dominique for the
charmless exclusive BFs, we are now able to compute the associated
systematic effect instead of taking the numbers from BAD540. We did this
for both the CLEO and BELLE ellipses. The net effect is a small increase
of the uncertainty when using CLEO numbers, and a more substantial
increase when using the BELLE numbers. Daniele has an explanation for
this effect, and he will report it at the meeting.
2) the theoretical error for the CLEO ellipse was still computed by
using the most distant (mb,a) points from the central values. Now all
the available points on the ellipse are taken into account and the
theoretical systematic uncertainty is defined as the maximum (positive
and negative) deviations from the default values when moving along the
ellipse. Please remember we are talking about partial branching
fractions, so the theoretical uncertainty in this case is a second order
effect with respect to other ones.
You will find more quantitative results in
http://www.slac.stanford.edu/~bozzi/tabelle.ps
there are 3 tables in that file. The first one is a copy of Table 2 of
the current BAD976, which I put for reference. The second table is
obtained by using CLEO numbers and by revaluating the theoretical and
signal modeling uncertainty as explained above (for this reason, all
columns but \sigma_{theo} and \sigma_{sig} are unchanged with respect to
the first table). The third one uses BELLE numbers. Each row represents
a q2 cut, the mx cut is 1.7 GeV.
Our conclusion is that we can safely switch to the Belle ellipse.
Regards, Concezio and Virginia.
