Two-baryon potentials and H-dibaryon from 3-flavor lattice QCD simulations

Baryon–baryon potentials are obtained from 3-flavor QCD simulations with the lattice volume L≃4fm, the lattice spacing a≃0.12fm, and the pseudo-scalar-meson mass Mps=469–1171MeV. The NN scattering phase-shifts and the mass of H-dibaryon in the flavor SU(3) limit are extracted from the resultant potentials by solving the Schrödinger equation. The NN phase-shifts in the SU(3) limit is shown to have qualitatively similar behavior as the experimental data. A bound H-dibaryon in the SU(3) limit is found to exist in the flavor-singlet JP=0+ channel with the binding energy of about 26 MeV for the lightest quark mass Mps=469MeV. Effect of flavor SU(3) symmetry breaking on the H-dibaryon is estimated by solving the coupled-channel Schrödinger equation for ΛΛ–NΞ–ΣΣ with the physical baryon masses and the potential matrix obtained in the SU(3) limit: a resonant H-dibaryon is found between ΛΛ and NΞ thresholds in this treatment.