Hidden-charm Hexaquarks from Lattice QCD

TL;DR

This study uses lattice QCD to investigate hidden-charm hexaquarks with specific quark content, calculating their masses and analyzing their potential stability relative to known thresholds, aiding future experimental searches.

Contribution

The paper provides the first lattice QCD calculations of hidden-charm hexaquark masses with multiple quantum numbers, extrapolating results to physical conditions.

Findings

All four hexaquarks have masses below the $\\Xi_c \bar{\Xi}_c$ threshold.

The $0^{-+}$ hexaquark is near the $\\eta_c K^+K^-$ threshold.

Results support the existence of stable or near-threshold multiquark states.

Abstract

We present a lattice QCD study of hidden-charm hexaquarks with quark content $usc\bar{d}\bar{s}\bar{c}$ based on four ensembles of gauge configurations generated by CLQCD Collaboration with pion mass in the range of 220-300MeV. Four operators with quantum numbers $0^{++}, 0^{-+}, 1^{++}$ and $1^{--}$ respectively are constructed to interpolate the hexaquarks. After validating the spectrum and the dispersion relation for ordinary hadrons, we calculate the masses of the hexaquarks and extrapolate the results to the physical pion mass and the continuum limit. We find that the masses of the four hexaquarks are all below the $\Xi_c \bar \Xi_c$ threshold, while the $0^{-+}$ hexaquark lies around the $\eta_c K^+K^-$ threshold. These results will be helpful for experimental searches in future and for a deep understanding of the nature of multiquark states.