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Ciao Concezio, On Fri, 29 Jul 2005, Concezio Bozzi wrote: > Hi, > it seems I have raised an interesting question, the answer to which is > more articulate than I thought... I propose to write back to Gil > something like: > > ...We feel that the extraction of the shape function parameters from the > b->sgamma spectrum is more sensitive to remaining theory uncertainties > and ansaetze for the SF than an approach based on the fit to moments. > However, we recognize that the debate on this issue is not settled yet > and we are willing to revisit the above assumption if in case... to be honest it is not true. They always supported the fit to the spectrum since the paper written by Kagan and Neubert (1998). The question regarding the ansaetze is not valid as we do (as Belle as well) a fit to the three ansaetzes. I think that the fair answer is that the paper has to clarify what is used and not to judge the theory. I then think then that the sentence: "However, there are concerns that the extraction of the shape function parameters from the photon spectrum in B->Xs gamma is less reliable" (p.18 before section 7) has to be removed. The fair thing is to specify that the parameters which are used come from the fit to the spectrum in the sentence just above that one. Again, I am happy to discuss further the issue, but I really believe that one has to give factual information and not make judgments on the theory. Thanks for raising this question, it is important to clarify it... Francesca