Hyperon-nucleon force from lattice QCD

We calculate potentials between a proton and a Ξ0 (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≃0.14fm. The ud quark mass in our study corresponds to mπ≃0.37 and 0.51 GeV, while the s quark mass corresponds to the physical value of mK. The central pΞ0 potential has a strong (weak) repulsive core in the S01 (S13) channel for r≲0.6fm, while the potential has attractive well at medium and long distances (0.6fm≲r≲1.2fm) in both channels. The sign of the pΞ0 scattering length and its quark mass dependence indicate a net attraction in both channels at low energies.