$\Lambda \Lambda$ and N$\Xi$ interactions from Lattice QCD near the physical point

Abstract

The $S$-wave $\Lambda \Lambda$ and $N\Xi$ interactions are studied on the basis of the (2+1)-flavor lattice QCD simulations close to the physical point ($m_{\pi }\simeq 146\mathrm{MeV}$ and $m_K\simeq 525\mathrm{MeV}$). Lattice QCD potentials in four different spin-isospin channels are extracted by using the coupled-channel HAL QCD method and are parametrized by analytic functions to calculate the scattering phase shifts. The $\Lambda \Lambda$ interaction at low energies shows only a weak attraction, which does not provide a bound or resonant dihyperon. The $N\Xi$ interaction in the spin-singlet and isospin-singlet channel is most attractive and lead the $N\Xi$ system near unitarity. Relevance to the strangeness=$-2$ hypernuclei as well as to two-baryon correlations in proton-proton, proton-nucleus and nucleus-nucleus collisions is also discussed.

16 pages, 8 figures