Coupled-channel scattering on a torus

Abstract

Based on the Hamiltonian formalism approach, a generalized L\"uscher's formula for two-particle scattering in both the elastic and coupled-channel cases in moving frames is derived from a relativistic Lippmann-Schwinger equation. Some strategies for extracting scattering amplitudes for a coupled-channel system from the discrete finite-volume spectrum are discussed and illustrated with a toy model of two-channel resonant scattering. This formalism will, in the near future, be used to extract information about hadron scattering from lattice quantum chromodynamics computations.