Baryon-Baryon Interaction of Strangeness S=-1 Sector

We present our recent studies on hyperon-nucleon (YN) interactions in the strangeness S=-1 that $p\Lambda, \Sigma^0 p$ and $\Sigma^+ n$, by extracting corresponding potentials through Nambu-Bethe-Salpeter wave functions. We calculate $\Lambda N$ and $\Sigma N$ potentials in the isospin I=3/2 channel, using the $N_f=2+1$ gauge configurations generated by PACS-CS collaboration and employing an improved method to obtain potentials in lattice QCD simulations. For the $^1S_0$ channel, the central $\Sigma N (I=3/2, ^1S_0)$ potential and the central $\Lambda N (^1S_0)$ potential are found to be very similar. In the spin triplet ($^3S_1-^3D_1$) channels, the central $\Lambda N(^3S_1-^3D_1)$ potential is attractive while the central $\Sigma N(I=3/2, ^3S_1-^3D_1)$ potentials is repulsive. Tensor potentials, on the other hand, are rather weak in the diagonal part of both $\Lambda N$ and $\Sigma N(I=3/2)$ systems.