Most Strange Dibaryon from Lattice QCD

The Ω Ω system in the ¹S₀ 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_π≃146 MeV at a lattice spacing of a ≃0.0846 fm . We show that lattice QCD data analysis by the HAL QCD method leads to the scattering length a₀=4.6 (6 )(-0.5_+1.2) fm , the effective range r_eff=1.27 (3 )(-0.03_+0.06) fm , and the binding energy B_{Ω Ω}=1.6 (6 )(-0.6_+0.7) MeV . These results indicate that the Ω Ω 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.