Speaker
Description
The interaction between the nucleon and charmonia ($J/\psi$ and $\eta_c$) is expected to deepen our understanding of various aspects in nonperturbative QCD ranging from the origin of nucleon mass to $J/\psi$ suppression in heavy ion collisions and properties of hidden-charm pentaquark states. Here, we present the first lattice QCD studies on low-energy $NJ/\psi$ and $N\eta_c$ interactions based on (2+1) flavor configurations with nearly physical pion mass $m_\pi=146$ MeV. The interactions, extracted from the spacetime correlations of nucleon and charmonium system by using HAL QCD method, are found to be attractive in all distances and manifest a characteristic long-range tail, which is consistent with the two-pion exchange interaction between a nucleon and a color-dipole. The resulting scattering lengths are around $0.4$ fm, $0.3$ fm and $0.2$ fm for $NJ/\psi$ with spin $1/2$, with spin $3/2$, and $N\eta_c$, respectively. Our results are orders of magnitude larger than those from the photo-production experiments assuming the vector meson dominance.
