Dibaryon with highest charm number near unitarity from lattice QCD

TL;DR

This study uses lattice QCD to investigate a potential dibaryon system composed of two triply charmed baryons, revealing it to be near the unitarity limit with a very large scattering length.

Contribution

First lattice QCD calculation of the $ ext{Omega}_{ccc} ext{Omega}_{ccc}$ dibaryon system near unitarity, including Coulomb effects and scattering parameters.

Findings

Scattering length $a^{C}_0 \,\simeq\,-19$ fm indicating strong attraction.

Effective range $r^{C}_{\mathrm{eff}} \simeq 0.45$ fm.

System is in the unitary regime with a small ratio of effective range to scattering length.

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 ${^1S_0}$ channel taking into account the Coulomb repulsion with the charge form factor of $\Omega_{ccc}$ leads to the scattering length $a^{\rm C}_0\simeq -19~\text{fm}$ and the effective range $r^{\rm C}_{\mathrm{eff}}\simeq 0.45~\text{fm}$. The ratio $r^{\rm C}_{\mathrm{eff}}/a^{\rm C}_0 \simeq -0.024$, whose magnitude is considerably smaller than that of the dineutron ($-0.149$), indicates that $\Omega_{ccc}\Omega_{ccc}$ is located in the unitary regime.