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.