HAL QCD method and Nucleon-Omega interaction with physical quark masses

Abstract

In lattice QCD, both direct method and HAL QCD method are used to investigate the two-baryon systems. We show that due to the contamination of the scattering excited states, it is challenging to measure the eigenenergy from the temporal correlation in the direct method, while the HAL QCD method can extract the information of the interaction from both scattering states and ground state by using the spatial correlation. We examine the systematic uncertainty of the derivative expansion in the HAL QCD method, which is found to be well under control at the low energies. By using the time-dependent HAL QCD method, we study the nucleon(N)-Omega(Ω) system in the 5 S 2 channel with almost physical quark masses at m π 146 MeV. We find the interaction is attractive at all distances, which produces a quasi-bound state with the binding energy 1.54(0.30)(+0.04 −0.10) MeV. We also consider the extra Coulomb interaction in the pΩ − (5 S 2) system, whose binding energy becomes 2.46(0.34)(+0.04 −0.01) MeV. NΩ(5 S 2) dibaryon could be searched through two-particle correlations in the heavy ion collision experiments.

Progress in Multibaryon Spectroscopy

“…Alternatives to the Lüscher formalism include the the potential method and the unitary isobar formalism. An enormous amount of progress both formal and numerical has been achieved, and new results and updates appear elsewhere in these proceedings [63,64,65,66,67,68]. Another approach is to put an EFT of interest into a finite volume and tune its low-energy constants to match the spectrum directly, rather than converting the energy levels to infinite-volume observables [69].…”