Three-Nucleon Forces explored by Lattice QCD Simulations

TL;DR

This paper uses lattice QCD simulations to investigate three-nucleon forces, revealing a repulsive core at short distances, and employs a simplified geometric setup to manage computational costs.

Contribution

It introduces a method to determine three-nucleon forces from lattice QCD using the NBS wave function with a simplified linear configuration.

Findings

Repulsive three-nucleon force at short distances

Successful extraction of 3NF from lattice QCD data

Utilization of a simplified geometric configuration to reduce computational cost

Abstract

We explore three-nucleon forces (3NF) from lattice QCD simulations. Utilizing the Nambu-Bethe-Salpeter (NBS) wave function, two-nucleon forces (2NF) and 3NF are determined on the same footing. Quantum numbers of the three-nucleon (3N) system are chosen to be (I, J^P)=(1/2,1/2^+) (the triton channel). The enormous computational cost is reduced by employing the simplest geometrical configuration, where 3N are aligned linearly with an equal spacing. We perform lattice QCD simulations using Nf=2 dynamical clover fermion configurations generated by CP-PACS Collaboration, at the lattice spacing of a = 0.156 fm on a 16^3 x 32 lattice with a large quark mass corresponding to m(\pi) = 1.13 GeV. Repulsive 3NF is found at short distance.