Speaker: Akaki Rusetsky (University of Bonn)
Title: Resonance matrix elements
Abstract: Using non-relativistic EFT in a finite volume, we construct a framework for the extraction of the resonance matrix elements from lattice data. The case of the decays $B\to K^*\ell^+\ell^-$ is considered in detail. In particular, using the EFT methods, we reproduce the multi-channel Lellouch-Luescher formula and carry out the analytic continuation of the form factors to the resonance pole by using the effective-range expansion for the matrix elements. The limit of the infinitely narrow resonances is studied.