Phenomenology of a double dilaton soft-wall model: Alpha strong from Ricci flow and pion Form Factors at intermediate-energy region

TL;DR

This paper introduces a holographic QCD model with a double dilaton and Ricci flow to study the running of the strong coupling, successfully matching non-perturbative and perturbative regimes and reproducing meson spectra and pion form factors.

Contribution

It presents a novel double dilaton holographic model incorporating Ricci flow to connect infrared fixed points with perturbative QCD, fitting meson data with minimal parameters.

Findings

Successful matching of non-perturbative and perturbative _s regimes

Reproduction of linear Regge trajectories and meson decay constants

Accurate modeling of pion form factors at intermediate energies

Abstract

Through a holographic model of QCD, we present a phenomenological approach to study the running of the strong coupling constant \alpha_s in both non-perturbative and perturbative regimes. The renormalization of the metric tensor, driven by the Ricci Flow, and the breaking of conformal and chiral symmetries -- thanks to introducing a double dilaton model and large-$N_c$ corrections -- allow us to relate the existence of an infrared fixed point in the coupling constant with a smooth matching to pQCD well above 2 GeV. This is done through a model with two fit parameters and one matching point. The proposed dilaton model yields linear Regge trajectories and decay constants for scalar, vector, and tensor meson families similar to their experimental counterparts. We finally study neutral and charged pion form factors to show an application of the running coupling constant obtained.