Electromagnetic transition amplitude for Roper resonance from holographic QCD

TL;DR

This paper uses a holographic QCD model to analyze the electromagnetic transition amplitude of the Roper resonance, successfully explaining recent experimental data and providing insights into baryon structure.

Contribution

It introduces a holographic QCD approach within the Sakai-Sugimoto model to study the Roper resonance's electromagnetic properties, addressing limitations of traditional quark models.

Findings

The model explains CLAS data on Roper resonance transitions.

Baryon structure is modeled with non-linear mesons and meson clouds.

The approach offers a new perspective on baryon excitations.

Abstract

The Roper resonance, the first excited state of the nucleon, Is one of the best-established baryon resonances. Yet, its properties have not been consistently explained by effective models of QCD, such as the non-relativistic quark model. In this letter, we propose an alternative approach in the Sakai-Sugimoto model that is one of the holographic models of QCD. In particular, we analyze the helicity amplitude of the electromagnetic transitions at the leading of 't~Hooft coupling $1/\lambda$. The model incorporates baryon structure at short distance by non-linear mesons surrounded by meson clouds at long distance. We demonstrate that the recently observed data by CLAS are explained in the present approach.