Holographic QCD Running Coupling Constant from the Ricci Flow

TL;DR

This paper introduces a holographic QCD model utilizing Ricci Flow to study the running of the strong coupling constant, connecting non-perturbative and perturbative regimes with a smooth transition at 2 GeV.

Contribution

It presents a novel holographic approach combining Ricci Flow and dilaton models to analyze the QCD coupling and meson spectra with minimal parameters.

Findings

Identifies an infrared fixed point in the coupling constant.

Achieves linear Regge trajectories for mesons.

Matches experimental decay constants.

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.