Updated Analysis of the Mass of the H Dibaryon from Lattice QCD

TL;DR

This paper presents an updated lattice QCD analysis indicating the H dibaryon is likely unbound by about 26 MeV, refining previous estimates and emphasizing its significance for understanding dense matter and neutron stars.

Contribution

The study provides a more precise lattice QCD estimate of the H dibaryon's binding energy, updating earlier results and highlighting its potential unbound state near the physical point.

Findings

H dibaryon is unbound by 26 ± 11 MeV.

Refined lattice QCD analysis improves previous estimates.

Implications for dense matter and neutron star physics.

Abstract

Recent lattice QCD calculations from the HAL and NPLQCD Collaborations have reported evidence for the existence of a bound state with strangeness -2 and baryon number 2 at quark masses somewhat higher than the physical values. A controlled chiral extrapolation of these lattice results to the physical point suggested that the state, identified with the famed H dibaryon, is most likely slightly unbound (by 13 $\pm$ 14 MeV) with respect to the $\Lambda--\Lambda$ threshold. We report the results of an updated analysis which finds the H unbound by 26 $\pm$ 11 MeV. Apart from the insight it would give us into how QCD is realized in Nature, the H is of great interest because of its potential implications for the equation of state of dense matter and studies of neutron stars. It may also explain the enhancement above the $\Lambda--\Lambda$ threshold already reported experimentally. It is clearly of great importance that the latter be pursued in experiments at the new J-PARC facility.