Nucleon-Nucleon Potential from Holography

TL;DR

This paper derives the nucleon-nucleon potential within holographic QCD by explicitly constructing two-instanton solutions, revealing a split into core and cloud contributions with specific meson exchange characteristics.

Contribution

It provides the first explicit two-instanton solution in holographic QCD and calculates the NN potential to order N_c/, detailing core and meson cloud effects.

Findings

Core NN interaction is repulsive in central, spin, and tensor channels.

Cloud contribution is dominated by omega, pion, and axial-vector exchanges.

Vector meson exchanges are subdominant across channels.

Abstract

In the holographic model of QCD, baryons are chiral solitons sourced by D4 flavor instantons in bulk of size 1/\sqrt{\lambda} with \lambda=g^2*N_c. Using the ADHM construction we explicit the exact two-instanton solution in bulk. We use it to construct the core NN potential to order N_c/\lambda. The core sources meson fields to order \sqrt{N_c/\lambda} which are shown to contribute to the NN interaction to order N_c/\lambda. In holographic QCD, the NN interaction splits into a small core and a large cloud contribution in line with meson exchange models. The core part of the interaction is repulsive in the central, spin and tensor channels for instantons in the regular gauge. The cloud part of the interaction is dominated by omega exchange in the central channel, by pion exchange in the tensor channel and by axial-vector exchange in the spin and tensor channels. Vector meson exchanges are subdominant in all channels.