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Ciao Alessio, thanks for the incredibly patient work you are doing ... There is something fishy in your results, but I hope we can converge easily now that you have done the bulk of the effort. A few preliminary remarks to try and understand what is going on: 1) the plots right above the first table of your page and the example you quote reports a situation which is not believable (if I understand correctly): huge changes in D(*)lnu which I can;t believe (you claim a factor 2 in Dlnu). And actually if I understand that the second table is the DlnuX BF table (can you please write it out explicitely?) the Dlnu almost does not change and the D*lnu is off by "only" 20%. 2) how much is the total B->(*,**)Dlnu systematics? 3) in the D branching fraction section, can you please show the Mx distributions also in the >1.6GeV region? 4) in the D BR systematics, did you adjust for the measured BF or for the DECAY.dec one? The measured BF might always have a selection bias. Also can you try doing the systematics varying only one well known BF (D0->KPi for istance) and checking the systematics actually comes negligible/? thanks ric On Fri, 17 May 2002, Alessio Sarti wrote: > Hi all, > the D systematics study has reach a crucial point. > You can see in the updated web page > (http://www.slac.stanford.edu/~asarti/recoil/sys ) > that the various D BR are extracted and the systematic is computed in a > 'new' way: > the BR are fixed to random values extracted accocrdingly to a gaussian > distribution centered at PDG with PDG values for the sigma. > > The systematic effect is REALLY large. This is a very conservative way to > extract the systematics. Sometimes we rely on the DECAY.DEC effect: the > generated BR is far from the PDG one. > Some other times is the PDG that has very large errors (this affect the > systematics only in a 'statistical' way..) > The other problems are coming of course from a BAD event reconstruction > and those are the most dangerous from our point of view. > the web page describes a little some of the main effects and > contributions, but the work to understand such large syst. is ongoing... > > Any comment and help is really appreciated. > > Alessio > > ______________________________________________________ > Alessio Sarti > Universita' & I.N.F.N. Ferrara > tel +39-0532-781928 Ferrara > roma +39-06-49914338 > SLAC +001-650-926-2972 > > "Vorrei tanto sapere chi e' che va in giro a costruire quadrati > sull'ipotenusa" > >