Meson spectrum and low-energy constants in large-$N$ QCD

TL;DR

This paper provides non-perturbative lattice results on the meson spectrum and low-energy constants in large-N QCD, revealing insights into meson trajectories and 1/N corrections up to order 1/N^3.

Contribution

It introduces a novel combination of TEK model simulations and finite-N results to compute meson properties and low-energy constants in the large-N limit of QCD.

Findings

Meson mass spectrum determined for large N

Radial Regge trajectories in π and ρ channels identified

Coefficients of 1/N expansion computed up to order 1/N^3

Abstract

We present new non-perturbative results about the meson spectrum and the low-energy constants of QCD in the 't Hooft large-$N$ limit, $N\to\infty$ with $N_{\scriptscriptstyle{\rm f}}/N\to 0$. These are obtained from lattice Monte Carlo simulations of the Twisted Eguchi-Kawai (TEK) model up to $N=841$. More precisely, we will discuss: our findings for the meson mass spectrum; the determination of the radial Regge trajectories in the $\pi$ and $\rho$ channels; the computation of the coefficients of the $1/N$ expansion of the chiral condensate, of the pion decay constant, and of the next-to-leading-order coupling $\bar{\ell}_4$, up to $\mathcal{O}(1/N^3)$ from the combination of TEK and standard finite-$N$ results.