Exotic bound states of two baryons in light of chiral effective field theory

TL;DR

This paper investigates baryon-baryon bound states with strangeness in various sectors using chiral effective field theory, connecting theoretical predictions with lattice QCD results and examining the impact of SU(3) breaking effects on the H-dibaryon.

Contribution

It provides a chiral effective field theory analysis of baryon-baryon bound states across different strangeness sectors, including the H-dibaryon, and compares predictions with lattice QCD data.

Findings

Binding energies for Xi-Xi 1S0 are consistent with lattice QCD results.

SU(3) breaking effects significantly influence the H-dibaryon's binding energy.

The H-dibaryon could be unbound at physical masses due to threshold effects.

Abstract

Baryon-baryon bound states in the strangeness S=-2, S=-3, and S=-4 sectors are considered. In particular, the dependence of the corresponding binding energies on the quark mass (or equivalently the pion mass) is explored in the framework of chiral effective field theory, in order to connect with current lattice QCD calculations. For a bound state in the Xi-Xi 1S0 channel, predicted by our leading-order effective field theory interaction, binding energies are inferred that are roughly in line with a recent lattice QCD result at meson and baryon masses that correspond to those in the lattice simulation. With regard to the so-called H-dibaryon it is shown that the SU(3) breaking effects induced by the differences of the pertinent two-baryon thresholds (Lambda-Lambda, Xi-N, Sigma-Sigma) have a very pronounced impact on its binding energy. A bound H-dibaryon as found in two lattice calculations could be shifted above the Lambda-Lambda or even above the Xi-N threshold for physical masses of the involved baryons.