Hyperons in nuclear matter from SU(3) chiral effective field theory

TL;DR

This paper uses chiral effective field theory within Brueckner theory to study hyperons in nuclear matter, providing insights into hyperon-nucleon interactions and their potential effects in nuclear environments.

Contribution

It introduces a consistent chiral EFT approach for hyperon-nucleon interactions in nuclear matter, including SU(3) symmetry and next-to-leading order calculations.

Findings

Sigma hyperons experience a repulsive potential in nuclear matter.

Lambda hyperons have a weak spin-orbit interaction.

Results align well with empirical data.

Abstract

Brueckner theory is used to investigate the properties of hyperons in nuclear matter. The hyperon-nucleon interaction is taken from chiral effective field theory at next-to-leading order with SU(3) symmetric low-energy constants. Furthermore, the underlying nucleon-nucleon interaction is also derived within chiral effective field theory. We present the single-particle potentials of Lambda and Sigma hyperons in symmetric and asymmetric nuclear matter computed with the continuous choice for intermediate spectra. The results are in good agreement with the empirical information. In particular, our calculation gives a repulsive Sigma-nuclear potential and a weak Lambda-nuclear spin-orbit force.