Speaker
Nico Gubernari
(technische universität münchen)
Description
We revisit soft gluon contributions to the "charm loop" effect in rare $B\to K^{(*)}ll$ decays, which is a large systematic uncertainty in the interpretation of the $b$-anomalies. Since these contributions are dominated by long-distance effects and are resistant to factorization attempts, we employ the method of light-cone sum rules to compute the relevant hadronic matrix elements. Our calculation extends previous works by considering the full set of the three-particle $B$-meson distribution amplitudes. We provide first numerical results, and discuss qualitatively their impact on the extraction of the Wilson coefficient $C_9$.
