Baryon masses at nonzero isospin/kaon density

TL;DR

This study uses lattice QCD to calculate how baryon energies shift in media of pions or kaons at specific masses, providing insights into baryon interactions at nonzero isospin/kaon densities.

Contribution

It introduces a lattice QCD approach to analyze baryon energy shifts in pion and kaon media at a fixed quark mass, extracting scattering parameters and low-energy constants.

Findings

Determined two- and three-body scattering parameters.

Extracted combinations of low-energy constants.

Analyzed energy shifts for multiple baryon-meson systems.

Abstract

We present a lattice QCD calculation of the ground-state energy shifts of various baryons in a medium of pions or kaons at a single value of the quark mass corresponding to a pion mass of m_\pi~390 MeV and a kaon mass of m_K~540 MeV, and in a spatial volume V (4fm)^3. All systems are created using a canonical formalism in which quark propagators are contracted into correlation functions of fixed isospin/kaon density. We study four different systems, \Sigma^+(\pi^+)^n, \Xi^0(\pi^+)^n, p(K^+)^n, and n(K^+)^n, for up to n=11 mesons. From the ground-state energy shifts we extract two- and three-body scattering parameters, as well as linear combinations of low-energy constants appearing in tree-level chiral perturbation theory.