Hyperon-nucleon force from lattice QCD

TL;DR

This study uses lattice QCD simulations to calculate the hyperon-nucleon potential between a proton and a Xi^0 hyperon, revealing repulsive cores and attractive regions that suggest overall attraction at low energies.

Contribution

It provides the first lattice QCD calculation of the hyperon-nucleon potential for the p-Xi^0 system, including detailed potential profiles and scattering length analysis.

Findings

Repulsive core in the potential at short distances.

Attractive potential at medium and long distances.

Net attraction indicated by scattering length analysis.

Abstract

We calculate potentials between a proton and a $\Xi^0$ (hyperon with strangeness -2) through the equal-time Bethe-Salpeter wave function, employing quenched lattice QCD simulations with the plaquette gauge action and the Wilson quark action on (4.5 fm)^4 lattice at the lattice spacing $a \simeq 0.14$ fm. The ud quark mass in our study corresponds to $m_{\pi}\simeq 0.37$ and 0.51 GeV, while the s quark mass corresponds to the physical value of $m_K$. The central $p \Xi^0$ potential has a strong (weak) repulsive core in the $^1S_0$ ($^3S_1$) channel for $r \lsim 0.6$ fm, while the potential has attractive well at the medium and long distances (0.6 fm $\lsim r \lsim 1.2$ fm) in both channels. The sign of the $p \Xi^0$ scattering length and its quark mass dependence indicate a net attraction in both channels at low energies.