Spin-2 NΩ dibaryon from lattice QCD

We investigate properties of the 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+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≃0.12 fm on a (1.9× 3.8 fm lattice. The ud and s quark masses in our study correspond to m_π=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 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.