Charming penguin and direct CP-violation in charmless B decays

Abstract

In the study of two-body charmless B decays as a mean of looking for direct CP-violation and measuring the CKM mixing parameters in the Standard Model, the short-distance penguin contribution with its absorptive part generated by charm quark loop seems capable of producing sufficient $B \to K\pi$ decays rates, as obtained in factorization and QCD-improved factorization models. However there are also long-distance charming penguin contributions which could give rise to a strong phase due to the rescattering $D^{*}D^{*}_{s} \to K\pi$ etc. In this talk, I would like to discuss recent works on the charming penguin contribution as a different approach to the calculation of these contributions in two-body charmless B decays. We find that the charming penguin contribution is significant for $B\to K\pi$ decays and, together with the tree and penguin terms, produces large branching ratios in agreement with data, though the analysis is affected by large theoretical uncertainties. The absorptive part due to the charmed meson intermediate states is found to produce large CP asymmetries for $B \to K\pi, \pi\pi$ decays.Comment: Talk given at the QCD Euroconference 2002, Montpellier 2-9 July 2002, LaTex, 7 pages, Misprint in the Tables correcte