Hyperon-Nucleon Interactions and the Composition of Dense Nuclear Matter from Quantum Chromodynamics

TL;DR

This paper uses Lattice QCD to calculate hyperon-nucleon interactions, providing insights into the role of strange quarks in dense nuclear matter relevant to astrophysics.

Contribution

It presents the first Lattice QCD calculations of neutron-Sigma^- interactions at near-physical pion mass, extrapolated to real-world conditions.

Findings

Interactions consistent with experimental data

Supports the importance of strange quarks in dense matter

Strengthens theoretical models of dense nuclear environments

Abstract

The low-energy neutron-Sigma^- interactions determine, in part, the role of the strange quark in dense matter, such as that found in astrophysical environments. The scattering phase shifts for this system are obtained from a numerical evaluation of the QCD path integral using the technique of Lattice QCD. Our calculations, performed at a pion mass of m_pi ~ 389 MeV in two large lattice volumes, and at one lattice spacing, are extrapolated to the physical pion mass using effective field theory. The interactions determined from QCD are consistent with those extracted from hyperon-nucleon experimental data within uncertainties, and strengthen theoretical arguments that the strange quark is a crucial component of dense nuclear matter.