Dibaryon with highest charm number near unitarity from lattice QCD

Abstract

A pair of triply charmed baryons, ${\Omega }_{ccc}{\Omega }_{ccc}$, is studied as an ideal dibaryon system by (2+1)-flavor lattice QCD with nearly physical light-quark masses and the relativistic heavy quark action with the physical charm quark mass. The spatial baryon-baryon correlation is related to their scattering parameters on the basis of the HAL QCD method. The ${\Omega }_{ccc}{\Omega }_{ccc}$ in the ${}^1{S}_0$ channel taking into account the Coulomb repulsion with the charge form factor of ${\Omega }_{ccc}$ leads to the scattering length $a_0^{\mathrm{C}}\simeq -19\text{fm}$ and the effective range $r_{\mathrm{eff}}^{\mathrm{C}}\simeq 0.45\text{fm}$. The ratio $r_{\mathrm{eff}}^{\mathrm{C}}/a_0^{\mathrm{C}}\simeq -0.024$, whose magnitude is considerably smaller than that of the dineutron ($-0.149$), indicates that ${\Omega }_{ccc}{\Omega }_{ccc}$ is located in the unitary regime.

Comments: 6 pages, 4 figures; Supplemental Material(1 page, 1 figure); Accepted for publication in Physical Review Letters