Spin-2 NΩ dibaryon from lattice QCD

We investigate properties of the N(nucleon)–Ω(Omega)N(nucleon)–Ω(Omega) interaction in lattice QCD to seek for possible dibaryon states in the strangeness −3 channel. We calculate the NΩ   potential through the equal-time Nambu–Bethe–Salpeter wave function in 2+12+1 flavor lattice QCD with the renormalization group improved Iwasaki gauge action and the nonperturbatively O(a)O(a) improved Wilson quark action at the lattice spacing a≃0.12a≃0.12 fm on a (1.9 fm)3×(1.9 fm)3× 3.8 fm lattice. The ud and s   quark masses in our study correspond to mπ=875(1) MeVmπ=875(1) MeV and mK=916(1) MeVmK=916(1) MeV. At these parameter values, the central potential in the S-wave with the spin 2 shows attractions at all distances. By solving the Schrödinger equation with this potential, we find one bound state whose binding energy is 18.9(5.0)(−1.8+12.1) MeV, where the first error is the statistical one, while the second represents the systematic error.