Hi,
I ran the analysis with different selector criteria for K+ and different
mass cuts for Ks.
First of all I observed that already with a Ks mass cut of 12MeV we gain
around 8% signal events with respect to the old cut (=no mass cut). This
is nice.
Then these are the results of the fit:
K+ selectors (all with a cut on Ks mass of +-12MeV)
sigma(ratioBR)
vloose 8.47%
loose 8.51%
tight 8.64%
vtight 8.54%
vtight selector is giving very strange results. Are we sure that the
bitma is correct? this result seems to be due to a very loose cut
(notapion or something). I will check. Urs, may you do the same?
Ks mass cuts (all with tight K+ selector)
sigma(ratioBR)
+-12 MeV 8.64%
+-10 MeV 8.63%
+- 8 MeV 8.65%
+-6.8MeV 8.64%
+-3.4MeV 8.74%
No striking effect is shown. The results are pretty compatible (small
changes are within the statistical fluctuations). The only different
results seems to be the one sigma cut (3.4MeV) on Ks.
My proposal is:
take the cuts we have at the moment
tight selector for K+
~3 sigma cut (12MeV) for Ks
Daniele
