More on a holographic dual of QCD

TL;DR

This paper explores the holographic dual of massless QCD, analyzing meson interactions, deriving coupling constants, and comparing theoretical predictions with experimental data, confirming vector meson dominance and decay structures.

Contribution

It provides a detailed analysis of meson interactions in holographic QCD, deriving relations among meson masses and couplings, and validating the model against experimental results.

Findings

Vector meson dominance in pion form factor confirmed

Decay amplitudes for  to  and  to 3 decay match theoretical structures

Most results are consistent with experimental data

Abstract

We investigate the interactions among the pion, vector mesons and external gauge fields in the holographic dual of massless QCD proposed in a previous paper, hep-th/0412141, on the basis of probe D8-branes embedded in a D4-brane background in type IIA string theory. We obtain the coupling constants by performing both analytic and numerical calculations, and compare them with experimental data. It is found that the vector meson dominance in the pion form factor as well as in the Wess-Zumino-Witten term holds in an intriguing manner. We also study the \omega to \pi\gamma and \omega to 3\pi decay amplitudes. It is shown that the interactions relevant to these decay amplitudes have the same structure as that proposed by Fujiwara et al. Various relations among the masses and the coupling constants of an infinite tower of mesons are derived. These relations play crucial roles in the analysis. We find that most of the results are consistent with experiments.