Extracting scattering parameters using the isospin chemical potential

TL;DR

This paper introduces a novel lattice QCD method using an isospin chemical potential to extract scattering parameters for processes involving annihilation diagrams, which are computationally challenging with traditional techniques.

Contribution

The paper proposes a new approach employing isospin chemical potential to study complex scattering processes with annihilation diagrams on the lattice.

Findings

Method enables extraction of scattering parameters involving annihilation diagrams.

Employs isospin chemical potential, which is computationally feasible in lattice QCD.

Provides a potential pathway to study previously inaccessible scattering processes.

Abstract

Hadronic scattering mediated through the strong interaction has been an area of great interest for both theory and experiment. Recently, lattice QCD calculations of scattering processes from first principles have seen remarkable progress, including multiple calculations of two-pion scattering lengths that agree with experiment to within a few percent. However, there exists a certain class of scattering processes, such as pion-nucleon scattering, that contain annihilation diagrams, which are often prohibitively expensive to simulate on the lattice. In this talk, I will present a method to extract certain parameters from this class of scattering processes by employing an isospin chemical potential, which can be simulated on the lattice as a result of its positive-definite fermion determinant.