Dibaryon with Highest Charm Number near Unitarity from Lattice QCD

Abstract

A pair of triply charmed baryons, ΩcccΩccc, 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 ΩcccΩccc in the ¹S₀ channel, taking into account the Coulomb repulsion with the charge form factor of Ωccc, leads to the scattering length a[C][0]≃−19 fm and the effective range r[C][eff]≃0.45 fm. The ratio r[C][eff]/a[C][0]≃−0.024, whose magnitude is considerably smaller than that of the dineutron (−0.149), indicates that ΩcccΩccc is located in the unitary regime.