Hoi, in general, the reference of choice is El Kahdra and Luke: hep-ph/0208114 And now I remember that we discussed this already once before. http://babar-hn.slac.stanford.edu:5090/HyperNews/get/ISLDecays/222.html The only caveat here is that I am not sure whether the correlation between lambda1 and lbar is taken into account. We should check it, of course. You can also get the writeup of the CKM workshop either in hardcopy in my office or from your (Italian) friends (PaoloG, AchilleS, MarcoB). I am not sure whether it is out already. Cheers, --U.