Speaker
Philipp Böer
(University of Mainz)
Description
Using diagrammatic resummation techniques, I discuss the double logarithmic series of B_c to eta_c form factors at large hadronic recoil. In the non-relativistic limit, mb >> mc >> LambdaQCD, this process provides one of the simplest setups to study the problem of endpoint singularities appearing in the SCET factorization of exclusive B decay amplitudes in a perturbative framework. The leading double logarithms arise from a peculiar interplay of energy-ordered ladder diagrams -- for which an RGE treatment using effective Theories is currently unknown -- as well as Standard Sudakov-type corrections.
