Lattice QCD Study of Positive Parity Dibaryons with Maximal Charm and Strangeness

Abstract

We present the ground-state energy spectra of dibaryons composed of single-flavor quarks, specifically systems with strangeness $\mathcal{S}=-6$ and charm $\mathcal{C}=6$. Our lattice QCD study is based on $N_f=2+1+1$ MILC ensembles with highly improved staggered quark (HISQ) sea quarks, spanning four lattice spacings and two spatial volumes. We employ valence quark propagators realized using a relativistic overlap action, evaluate correlation matrices with carefully designed operator bases, and extract reliable ground-state energy estimates in the $S=0$ and $S=2$ spin channels. We explore their binding characteristics and interaction dynamics by examining the energy separation between the dibaryon states and the corresponding two-baryon thresholds. These results contribute to a deeper understanding of single-flavor dibaryon states as a function of the quark masses. In the $S=0$ channel, the ${\Omega }_{ccc}$-${\Omega }_{ccc}$ system exhibits a clear signal of a bound state, while the $\Omega$-$\Omega$ system lies very close to the threshold, making it difficult to draw definitive conclusions. For $S=2$, both systems are found to be unbound.

Comments: v2: 15 pages, 8 tables, 10 main text figures, and 2 appendices figures. No change in results and version consistent with Published PRD version