Spin-2 NΩ dibaryon from lattice QCD

We investigate properties of the N(nucleon)-Omega(Omega) interaction in lattice QCD to seek for possible dibaryon states in the strangeness -3 channel. We calculate the N Omega potential through the equal-time Nambu-Bethe-Salpeter wave function in 2 + 1 flavor lattice QCD with the renormalization group improved Iwasaki gauge action and the nonperturbatively O(a) improved Wilson quark action at the lattice spacing a similar or equal to 0.12 fm on a (1.9 fm)(3) x 3.8 fm lattice. The ud and s quark masses in our study correspond to m(pi) = 875(1) MeV and m(K) = 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 Schrodinger equation with this potential, we find one bound state whose binding energy is 18.9(5.0) ((+12.1)(-1.8)) MeV, where the first error is the statistical one, while the second represents the systematic error. (C) 2014 Elsevier B.V. All rights reserved.