LATTICE QCD SIMULATION OF HYPERON-NUCLEON POTENTIAL

We calculate pΞ⁰ potentials from the equal-time Bethe-Salpeter amplitude measured in the quenched QCD simulation with the spatial lattice volume, (4.4 fm)³. The standard Wilson gauge action with the gauge coupling β = 5.7 on 32⁴ lattice together with the standard Wilson quark action is used. The hopping parameter κ_ud = 0.1678 is chosen for u and d quarks, which corresponds to m_π ≃ 0.37 GeV. The physical strange quark mass is used by taking the parameter κ_s = 0.1643 which is deduced from the physical K meson mass. The lattice spacing a = 0.1420 fm is determined by the physical ρ meson mass. We find that the pΞ⁰ potential has sizable spin dependence. Strong repulsive core is found in ¹S₀ channel while the effective central potential in the ³S₁ channel has relatively weak repulsive core. The potentials also have weak attractive parts in the medium to long distance region (0.6 fm ≲ r ≲ 1.2 fm) in both of the ¹S₀ and ³S₁ channels.