2017/07/18 by Colin Morningstar, John Bulava, Bijit Singha +4 · 2 citations
Physics and Astronomy · #hep-lat
paper · pdf · doi:10.1016/j.nuclphysb.2017.09.014
32 pages, 1 figure
arxiv created 2017/07/18 · arxiv updated 2018/03/14
An implementation of estimating the two-to-two K-matrix from finite-volume energies based on the Lüscher formalism and involving a Hermitian matrix known as the "box matrix" is described. The method includes higher partial waves and multiple decay channels. Two fitting procedures for estimating the K-matrix parameters, which properly incorporate all statistical covariances, are discussed. Formulas and software for handling total spins up to S=2 and orbital angular momenta up to L=6 are obtained for total momenta in several directions. First tests involving ρ-meson decay to two pions include the L=3 and L=5 partial waves, and the contributions from these higher waves are found to be negligible in the elastic energy range.