Hi all, 

here is the status of the MC fits. First of all: what is our generation
value for BRBR? From the DECAY.DEC of both SP5 and SP6 we see 

BR(Xclnu) = 10.4%
BR(Xulnu) =  0.21% 

So it seems that BRBR(gen) = 0.21/(10.4+0.21) = 198*10^-4
But if you take the numbers from the MC truth on the ntuples, we get 
on the Mx fit _without_ signal unfolding: 
 
Vub events (truth-matched) passing the SL selection and with mX<1.55:
9705
total SL events (truth-matched): 434239
pstarfactor (truth-matched): 1.05

===> BRBR (from MC truth): 9705/434239/1.05 = 213*10^-4 

The Mx fit without unfolding gives (229+/-7+-6)*10^-4. In this fit the
same MC sample (generic BB Run1-4) has been used as both data and MC.
This is not the right thing to do, but at least it shows the effect due
to mES fits, since they are done on "data" only whereas we are simply
counting the truth-matched events for MC. 
Results from this fit are at 

http://www.slac.stanford.edu/~bozzi/scra/IbuMCmXfixVubfixResfixSB/

 
The fit with signal unfolding is still not ready yet, at the moment
there is a problem in getting the right phase space acceptance (i.e. the
one from DFN as it comes out from DECAY.DEC). We will post a recipe on
how to run MC fits as soon as we are convinced that we are doing the
right thing on signal-unfolded MX fits. The difficult part is to check
that we are not applying any reweighting on the MC, since our data set
is MC without reweighting. 
Ciao, Concezio & Antonio.