Comments on Mesonic Correlators in the Worldline Formalism

TL;DR

This paper extends the worldline formalism to include mesonic correlators, exploring applications to QCD-like theories, large-N_c models, and holography, providing new insights into meson dynamics and QCD limits.

Contribution

It introduces a method to incorporate mesonic correlators into the worldline formalism and analyzes their implications in various QCD-like theories and limits.

Findings

Relation of large-N_c 2D QCD to a harmonic oscillator

Dependence of Peskin S-parameter on flavor number and representation

Discussion of Veneziano limit in holography

Abstract

We elaborate on how to incorporate mesonic correlators into the worldline formalism. We consider possible applications to QCD-like theories in various dimensions. We focus on large-N_c two dimensional QCD (the 't Hooft model) and relate it to a single harmonic oscillator. We also discuss the dependence of the Peskin S-parameter on the number of massless flavors and their representation and compare our expression to the corresponding expression obtained at weak coupling. Finally, we use the worldline formalism to discuss how the Veneziano limit of QCD is realized in holography in the limit of small N_f/N_c.