A study of hyperons in nuclear matter based on chiral effective field theory

TL;DR

This paper investigates hyperon properties in nuclear matter using chiral effective field theory, revealing a repulsive Sigma potential and a weak Lambda-nucleus spin-orbit interaction, with implications for hypernuclear physics.

Contribution

It applies chiral effective field theory to hyperon-nucleon interactions in nuclear matter, providing new insights into hyperon potentials and spin-orbit effects.

Findings

Sigma-nucleus potential is repulsive.

Weak Lambda-nucleus spin-orbit interaction can be modeled.

Results align with phenomenological data.

Abstract

The in-medium properties of a hyperon-nucleon potential, derived within chiral effective field theory and fitted to Lambda-N and Sigma-N scattering data, are investigated. Results for the single-particle potentials of the Lambda and Sigma hyperons in nuclear matter are reported, based on a conventional first-order Brueckner calculation. The Sigma-nucleus potential is found to be repulsive, in agreement with phenomenological information. A weak Lambda-nucleus spin-orbit interaction can be achieved by an appropriate adjustment of a low-energy constant corresponding to an antisymmetric Lambda-N -- Sigma-N spin-orbit interaction that arises at next-to-leading order in the effective field theory approach.