A Matrix Model for Baryons and Nuclear Forces

TL;DR

This paper introduces a matrix model for multi-baryon systems derived from string theory, providing new insights into baryon size, spectra, and short-range nuclear forces within holographic QCD.

Contribution

It presents a novel matrix model for baryons based on open string theory, improving the understanding of baryon dynamics and nuclear forces at short distances in holographic QCD.

Findings

Derived a new size for holographic baryons.

Obtained a precise form of the nucleon repulsive core.

Computed baryon spectra and short-distance nuclear forces.

Abstract

We propose a new matrix model describing multi-baryon systems. We derive the action from open string theory on the wrapped baryon vertex D-branes embedded in the D4-D8 model of large N holographic QCD. The positions of k baryons are unified into k x k matrices, with spin/isospin of the baryons encoded in a set of k-vectors. Holographic baryons are known to be very small in the large 't Hooft coupling limit, and our model offers a better systematic approach to dynamics of such baryons at short distances. We compute energetics and spectra (k=1), and also short-distance nuclear force (k=2). In particular, we obtain a new size of the holographic baryon and find a precise form of the repulsive core of nucleons. This matrix model complements the instanton soliton picture of holographic baryons, whose small size turned out to be well below the natural length scale of the approximation involved there. Our results show that, nevertheless, the basic properties of holographic baryons obtained there are robust under stringy corrections within a few percents.