I have done a little Maple study on efficiency concerning the
a-parameter. The purpose of the exercise is to get a feeling for the
systematics.
http://www.slac.stanford.edu/~elsen/efficiency.pdf
I have tried to model the efficiency dependence according to the BAD.
If I fold that distribution with two Mx distributions that roughly
agree with what is caused by the variation of the a-parameter I can
study the variation of the number of events below 1.55 in Mx.
The original model distributions differ by <7%. After folding with the
efficiency the effect translates into a 20% variation in the number of
events and hence on the branching ratio. Surprisingly the largest
variation is at the rho-peak.
It is thus important that in all these studies the differential
efficiency is properly applied. Incidentally do you have the efficiency
distribution for the non-resonant model? I am worried that what is
called efficiency may be a convolution of efficiency and resolution.
Eckhard
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