$\Lambda_c-N$ interaction from lattice QCD

Abstract

We investigate the s-wave $\Lambda_c-N$ interaction for spin singlet systems($^1S_0$) using the HAL QCD method. In our lattice QCD simulations, we employ gauge configurations generated by the PACS-CS Collaboration at $a = 0.0907(13)$ fm on a $32^3 \times 64$ lattice ($La = 2.902(42)$ fm). We employ two ensembles, one at $m_\pi = 700(1)$ MeV and the other at $m_\pi = 570(1)$ MeV to study the quark mass dependence of the $\Lambda_c-N$ interactions. We calculate a $^1S_0$ central potential not only for the $\Lambda_c-N$ system but also for $\Lambda-N$ system to understand the role of heavy charm quarks in $\Lambda_c-N$ system. We find repulsion at short distance and attraction at mid-range for both the $\Lambda_c-N$ and the $\Lambda-N$ potentials. The short range repulsion of the $\Lambda_c-N$ potential is smaller than that of the $\Lambda-N$ potential, and the attraction of the $\Lambda_c-N$ potential is small compared with the $\Lambda-N$ potential. The phase shift and scattering length calculated with these potentials show that there exist no bound state for both the $\Lambda_c-N$ and $\Lambda-N$ systems for $m_{\pi} > 570$ MeV.