Two-Baryon Potentials and H-Dibaryon from 3-flavor Lattice QCD Simulations

TL;DR

This study uses 3-flavor lattice QCD simulations to derive baryon-baryon potentials, revealing a bound H-dibaryon in the SU(3) limit and a possible resonance when flavor symmetry breaking is considered.

Contribution

It provides the first lattice QCD calculation of baryon-baryon potentials and the H-dibaryon, including effects of flavor SU(3) symmetry breaking.

Findings

A bound H-dibaryon exists in the SU(3) limit with about 26 MeV binding energy.

The NN phase shift in the SU(3) limit resembles experimental data.

A resonant H-dibaryon is suggested between Lambda Lambda and N Xi thresholds when symmetry breaking is included.

Abstract

Baryon-baryon potentials are obtained from 3-flavor QCD simulations with the lattice volume L ~ 4 fm, the lattice spacing a ~ 0.12 fm, and the pseudo-scalar-meson mass M_ps =469 - 1171 MeV. The NN scattering phase shift and the mass of H-dibaryon in the flavor SU(3) limit are extracted from the resultant potentials by solving the Schrodinger equation. The NN phase shift 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 J^P=0^+ channel with the binding energy of about 26 MeV for the lightest quark mass M_ps = 469 MeV. Effect of flavor SU(3) symmetry breaking on the H-dibaryon is estimated by solving the coupled-channel Schrodinger equation for Lambda Lambda - N Xi - Sigma Sigma with the physical baryon masses and the potential matrix obtained in the SU(3) limit: a resonant H-dibaryon is found between Lambda Lambda and N Xi thresholds in this treatment.