Lattice QCD approach to nuclear force

TL;DR

This paper uses lattice QCD simulations to derive the nucleon-nucleon potential, revealing key features like the repulsive core and attractive well, and studies how these features depend on quark mass.

Contribution

The study provides updated lattice QCD results for the NN potential, demonstrating its qualitative features and quark mass dependence, which advances understanding of nuclear forces from first principles.

Findings

NN potential exhibits repulsive core and attractive well

Quark mass reduction enhances both core and well features

Potential reproduces scattering length in the infinite volume limit

Abstract

We present our updated results of the nucleon-nucleon potential in quenched lattice QCD simulations with the plaquette gauge action and the Wilson quark action on the 32^4(\simeq (4.4 fm)^4) lattice. From the equal-time Bethe-Salpeter (BS) wave function, the NN potential is constructed through the Schroedinger-type equation. Resulting NN potential has all the qualitative features which phenomenological potentials commonly have: the repulsive core at short distance and the attractive well at medium and long distances. In the L \to \infty limit, our NN potential is guaranteed to reproduce the scattering length obtained from the Luescher's formula. The quark mass dependence of the NN potential is studied with m_{pi} \sim 380, 529, 731 MeV. The results suggest that both the repulsive core at short distance and the attractive well at medium distance are enhanced in the light quark mass region.