Charmonium-nucleon potential from lattice QCD

TL;DR

This study calculates the charmonium-nucleon potential using lattice QCD, revealing weak attraction at short distances and screening at large distances, which is crucial for understanding charmonium bound states in nuclei.

Contribution

First lattice QCD calculation of charmonium-nucleon potential from Bethe-Salpeter amplitudes, providing detailed interaction insights.

Findings

Potential is weakly attractive at short distances.

Potential is exponentially screened at large distances.

J/psi-N potential is slightly more attractive than eta_c-N.

Abstract

We present results for charmonium-nucleon potential $V_{c\bar{c}-N}(r)$ from quenched lattice QCD, which is calculated from the equal-time Bethe-Salpeter amplitude through the effective Schr\"odinger equation. Detail information of the low-energy interaction between the nucleon and charmonia ($\eta_c$ and $J/\psi$) is indispensable for exploring the formation of charmonium bound to nuclei. Our simulations are performed at a lattice cutoff of $1/a\approx 2.1$ GeV in a spatial volume of $(3 fm)^3$ with the nonperturbatively $O(a)$ improved Wilson action for the light quarks and a relativistic heavy quark action for the charm quark. We have found that the potential $V_{c\bar{c}-N}(r)$ for either the $\eta_c$ and $J/\psi$ states is weakly attractive at short distances and exponentially screened at large distances. The spin averaged $J/\psi$-$N$ potential is slightly more attractive than that of the $\eta_c$-$N$ case.