Nucleus from String Theory

TL;DR

This paper demonstrates that in holographic QCD models derived from string theory, baryons naturally form nuclei with radii proportional to A^{1/3}, aligning with empirical data, using generic D-brane properties and specific holographic models.

Contribution

It shows that nuclear radius scaling emerges naturally in holographic QCD, supported by both generic D-brane properties and a concrete Sakai-Sugimoto model analysis.

Findings

Nuclear radius scales as A^{1/3} in holographic QCD.

Nucleons are bound in a finite volume.

Theoretical radius matches experimental values.

Abstract

In generic holographic QCD, we find that baryons are bound to form a nucleus, and that its radius obeys the empirically-known mass number (A) dependence r A^{1/3} for large A. Our result is robust, since we use only a generic property of D-brane actions in string theory. We also show that nucleons are bound completely in a finite volume. Furthermore, employing a concrete holographic model (derived by Hashimoto, Iizuka, and Yi, describing a multi-baryon system in the Sakai-Sugimoto model), the nuclear radius is evaluated as O(1) x A^{1/3} [fm], which is consistent with experiments.