Long - distance effects in B → V γ radiative weak decays


A systematic approach to long-distance effects in exclusive radiative weak B decays is presented, based on a combination of the heavy quark limit with perturbative QCD. The dominant long-distance effects, connected with weak annihilation and W -exchange topologies, can be computed in a modelindependent way using experimental data on B radiative leptonic decays. Nonfactorizable corrections vanish in the chiral limit and to leading twist. The left-handed photon amplitudes are shown to be enhanced relative to the right-handed ones, both in the longand short-distance parts of the amplitude. Recent CLEO data on B → K∗γ decays are consistent with Standard Model estimates of the long-distance contributions, and disfavor an enhanced gluonic penguin contribution. We discuss the implications of our results for the extraction of |Vtd|. A new method for determining the weak phase α using radiative weak decays is presented. Typeset using REVTEX

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@inproceedings{Grinstein2000LongD, title={Long - distance effects in B → V γ radiative weak decays}, author={Benjam{\'i}n Grinstein and Dan Pirjol}, year={2000} }