Scattering from finite-volume energies including higher partial waves and multiple decay channels

TL;DR

This paper introduces a simplified and comprehensive method for extracting two-to-two $K$-matrix elements from finite-volume energies, accounting for higher partial waves and multiple decay channels, with proper statistical treatment.

Contribution

It presents a new implementation based on the Luescher formalism that includes higher partial waves and multiple channels, improving accuracy and simplicity over previous methods.

Findings

Method includes covariances and uncertainties properly.

Formulas and software handle spins up to S=2 and angular momenta up to L=6.

Simplifies the extraction process compared to earlier procedures.

Abstract

A new implementation of estimating the two-to-two $K$-matrix from finite-volume energies based on the Luescher formalism is described. The method includes higher partial waves and multiple decay channels, and the fitting procedure properly includes all covariances and statistical uncertainties. The method is also simpler than previously used procedures. Formulas and software for handling total spins up to $S=2$ and orbital angular momenta up to $L=6$ are presented.