Most Strange Dibaryon from Lattice QCD

Abstract

The $\Omega \Omega$ system in the ${}^1{S}_0$ channel (the most strange dibaryon) is studied on the basis of the (2+1)-flavor lattice QCD simulations with a large volume (8.1 fm)${}^3$ and nearly physical pion mass $m_{\pi }\simeq 146$ MeV at a lattice spacing $a\simeq 0.0846$ fm. We show that lattice QCD data analysis by the HAL QCD method leads to the scattering length $a_0=4.6(6){(}_{-0.5}^{+1.2})\mathrm{fm}$, the effective range $r_{\mathrm{eff}}=1.27(3){(}_{-0.03}^{+0.06})\mathrm{fm}$ and the binding energy $B_{\Omega \Omega }=1.6(6){(}_{-0.6}^{+0.7})\mathrm{MeV}$. These results indicate that the $\Omega \Omega$ system has an overall attraction and is located near the unitary regime. Such a system can be best searched experimentally by the pair-momentum correlation in relativistic heavy-ion collisions.

Comments: 6 pages and 4 figures