Scattering phases for meson and baryon resonances on general moving-frame lattices

TL;DR

This paper generalizes L"uscher's formalism to compute scattering phases for meson and baryon resonances with various angular momenta and momenta, enhancing the analysis of lattice QCD data.

Contribution

It extends the L"uscher method to include S, P, D waves and arbitrary total momenta for meson and baryon resonances on finite-volume lattices.

Findings

Formalism applicable to a wider range of resonances.

Improved access to energy levels with nonzero momenta.

Level crossing shifts to smaller pion masses.

Abstract

A proposal by L\"uscher enables one to compute the scattering phases of elastic two-body systems from the energy levels of the lattice Hamiltonian in a finite volume. In this work we generalize the formalism to S--, P-- and D--wave meson and baryon resonances, and general total momenta. Employing nonvanishing momenta has several advantages, among them making a wider range of energy levels accessible on a single lattice volume and shifting the level crossing to smaller values of $m_\pi L$.