Continuum limit of baryon-baryon scattering with SU(3) flavor symmetry

TL;DR

This study uses lattice QCD to analyze baryon-baryon scattering at the SU(3) flavor symmetric point, revealing significant discretization effects on the binding energy of the $H$ dibaryon and providing preliminary results for other channels.

Contribution

First lattice QCD calculation of baryon-baryon scattering at multiple lattice spacings with focus on the $H$ dibaryon, highlighting discretization effects.

Findings

Continuum binding energy of $H$ dibaryon: 4.56 MeV with uncertainties.

Discretization effects increase the binding energy by a factor of 7.5 on coarse lattices.

Preliminary phase shift results for $D$-wave and nucleon-nucleon channels.

Abstract

We report a study of the scattering of two octet baryons using lattice QCD. The baryon-baryon spectrum is computed using distillation on eight lattice ensembles spanning six lattice spacings and multiple volumes, all at the SU(3) flavor symmetric point with $m_\pi=m_K\approx 420$ MeV. Using finite-volume quantization conditions, we determine the scattering phase shift and the presence of bound states. Focusing on the $H$ dibaryon, our results show large discretization effects: in the continuum, the binding energy is $B_H=4.56\pm1.13\pm0.63$ MeV, whereas on our coarsest lattice spacing this is larger by a factor of about 7.5. We also present preliminary results for a $D$-wave phase shift and for the spectrum in the nucleon-nucleon ${}^1S_0$ channel.