NΩ dibaryon from lattice QCD near the physical point

The nucleon(N)-Omega(Omega) system in the S-wave and spin-2 channel (S-5(2)) is studied from the (2+1)-flavor lattice QCD with nearly physical quark masses (m(pi) similar or equal to 146 MeV and m(K) similar or equal to 525 MeV). The time- dependent HAL QCD method is employed to convert the lattice QCD data of the two-baryon correlation function to the baryon-baryon potential and eventually to the scattering observables. The N Omega(S-5(2)) potential, obtained under the assumption that its couplings to the D-wave octet-baryon pairs are small, is found to be attractive in all distances and to produce a quasi-bound state near unitarity: In this channel, the scattering length, the effective range and the binding energy from QCD alone read a(0) = 5.30(0.44)((+0.16)(-0.01)) fm, r(eff) = 1.26(0.01)((+0.02)(-0.01)) fm, B = 1.54(0.30)((+0.04)(-0.10)) MeV, respectively. Including the extra Coulomb attraction, the binding energy of p Omega(-)(S-5(2)) becomes Bp Omega- = 2.46(0.34)((+0.04)(-0.11)) MeV. Such a spin-2 p Omega(-) state could be searched through two-particle correlations in p-p, p-nucleus and nucleus-nucleus collisions. (C) 2019 The Author(s). Published by Elsevier B.V.