# Lattice-QCD Determination of the Hyperon Axial Couplings in the Continuum Limit

## TL;DR

This paper reports the first continuum limit calculation of hyperon axial couplings using $N_f=2+1+1$ lattice QCD, including systematic uncertainties and physical pion mass, providing key parameters for hyperon physics and neutron star models.

## Contribution

It introduces the first direct lattice QCD calculation of $g_{ ext{Sigma Sigma}}$ and $g_{ ext{Xi Xi}}$ at the physical pion mass with comprehensive systematic error analysis.

## Key findings

- Hyperon axial couplings determined: $g_{ ext{Sigma Sigma}}=0.4455$ and $g_{ ext{Xi Xi}}=-0.2703$.
- SU(3) symmetry breaking estimated at 9%, smaller than previous lattice estimates.
- Provides low-energy constants D and F with improved precision.

## Abstract

We present the first continuum extrapolation of the hyperon octet axial couplings ($g_{\Sigma \Sigma}$ and $g_{\Xi \Xi}$) from $N_f=2+1+1$ lattice QCD. These couplings are important parameters in the low-energy effective field theory description of the octet baryons and fundamental to the nonleptonic decays of hyperons and to hyperon-hyperon and hyperon-nucleon scattering with application to neutron stars. We use clover lattice fermion action for the valence quarks with sea quarks coming from configurations of $N_f=2+1+1$ highly improved staggered quarks (HISQ) generated by MILC Collaboration. Our work includes the first calculation of $g_{\Sigma \Sigma}$ and $g_{\Xi \Xi}$ directly at the physical pion mass on the lattice, and a full account of systematic uncertainty, including excited-state contamination, finite-volume effects and continuum extrapolation, all addressed for the first time. We find the continuum-limit hyperon coupling constants to be $g_{\Sigma \Sigma}=0.4455(55)_\text{stat}(65)_\text{sys}$ and $g_{\Xi \Xi} =-0.2703(47)_\text{stat}(13)_\text{sys}$, which correspond to low-energy constants of $D = 0.708(10)_\text{stat}(6)_\text{sys}$ and $F = 0.438(7)_\text{stat}(6)_\text{sys}$. The corresponding SU(3) symmetry breaking is 9\% which is about a factor of 2 smaller than the earlier lattice estimate.