S-wave scattering of strangeness -3 baryons

Abstract

We explore the interactions of two strangeness -3 baryons in multiple spin channels with lattice QCD. This system provides an ideal laboratory for exploring the interactions of multi-baryon systems with minimal dependence on light quark masses. Model calculations of the two-${\Omega }^{-}$ system in two previous works have obtained conflicting results, which can be resolved by lattice QCD. The lattice calculations are performed using two different volumes with $L\sim 2.5$ and 3.9 fm on anisotropic clover lattices at $m_{\pi }\sim 390$ MeV with a lattice spacing of $a_s\sim 0.123$ fm in the spatial direction and $a_t\sim a_s/3.5$ in the temporal direction. Using multiple interpolating operators from a non-displaced source, we present scattering information for two ground state ${\Omega }^{-}$ baryons in both the S=0 and S=2 channels. For S=0, $k\cot \delta$ is extracted at two volumes, which lead to an extrapolated scattering length of $a_{S=0}^{\Omega \Omega }=0.16\pm 0.22\text{fm}$, indicating a weakly repulsive interaction. Additionally, for S=2, two separate highly repulsive states are observed. We also present results on the interactions of the excited strangeness -3, spin-1/2 states with the ground spin-3/2 states for the spin-1 and spin-2 channels. Results for these interactions are consistent with attractive behavior.

Comments: 21 pages, 10 figs