Charge symmetry breaking in light $\Lambda$ hypernuclei

TL;DR

This paper reviews recent theoretical calculations addressing charge symmetry breaking in light hypernuclei, focusing on the role of $ extLambda$-$ extSigma^0$ mixing and shell-model approaches to understand observed CSB effects.

Contribution

It introduces a shell-model approach to charge symmetry breaking in p-shell hypernuclei and reviews four-body no-core shell model calculations incorporating $ extLambda$-$ extSigma^0$ mixing within chiral effective field theory.

Findings

CSB is notably strong in A=4 hypernuclei.

$ extLambda$-$ extSigma^0$ mixing explains observed CSB effects.

Shell-model approaches can effectively describe CSB in hypernuclei.

Abstract

Charge symmetry breaking (CSB) is particularly strong in the A=4 mirror hypernuclei $_{\Lambda}^4$H--$_{\Lambda}^4$He. Recent four-body no-core shell model calculations that confront this CSB by introducing $\Lambda$-$\Sigma^0$ mixing to leading-order chiral effective field theory hyperon-nucleon potentials are reviewed, and a shell-model approach to CSB in p-shell $\Lambda$ hypernuclei is outlined.