NΩN\Omega dibaryon from lattice QCD near the physical point

The nucleon($N$)-Omega($\Omega$) system in the S-wave and spin-2 channel ($^5$S$_2$) is studied from the (2+1)-flavor lattice QCD with nearly physical quark masses ($m_\pi \simeq 146$~MeV and $m_K \simeq 525$~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 $N\Omega$($^5$S$_2$) 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, $r_{\rm eff} = 1.26(0.01)(^{+0.02}_{-0.01})$~fm, $B = 1.54(0.30)(^{+0.04}_{-0.10})$~MeV, respectively. Including the extra Coulomb attraction, the binding energy of $p\Omega^-$($^5$S$_2$) becomes $B_{p\Omega^-} = 2.46(0.34)(^{+0.04}_{-0.11})$~MeV. Such a spin-2 $p\Omega^-$ state could be searched through two-particle correlations in $p$-$p$, $p$-nucleus and nucleus-nucleus collisions.Comment: 16 pages, 6 figures, a reference adde

The effect of phenomenological Λα potentials in (_ΛΛ^6)He hypernuclei by using modern ΛΛ potential derived from lattice QCD

Recently, the ΛΛ potential at nearly physical quark masses has been calculated in the lattice QCD simulations by the HAL QCD Collaboration which are the most consistent potential with the experimental data. In this study making use of this ΛΛ interaction the binding energy and the radius matter for the ground state of hypernucleus (_ΛΛ^6)He is calculated via solving the coupled Faddeev equations. Here, for the Λα interaction; three different and common types of interactions, the Isle-type potential, the single Gaussian potential and the Maeda-Schmidt potential are examined. Numerical analyzes for (_ΛΛ^6)He using three ΛΛ interaction models and three models of phenomenological Λα interaction lead to the values of ground state energy between 7.197 and 8.408 MeV, and the value of the radius of matter in the range of 1.731 to 1.954 fm. Numerical results show that the minimum value of ground state binding energy, which is closest to the experimental value, occurs when one uses the HAL QCD ΛΛ potential at lattice time t⁄a=12 and the MS phenomenological type Λα potential. Also, the geometrical properties of (_ΛΛ^6)He system are investigated