A theoretical study of meson transition form factors

TL;DR

This thesis provides a data-driven theoretical analysis of meson transition form factors, with applications to meson mixing, rare decays, and muon magnetic moment calculations, emphasizing the importance of empirical methods.

Contribution

It introduces a rational, data-based framework for describing meson transition form factors across various energy regions, improving accuracy and reducing systematic errors.

Findings

Accurate description of meson form factors in spacelike and low-energy timelike regions.

Application to eta-eta' mixing and rare decay processes.

Assessment of pseudoscalar-pole contributions to muon g-2.

Abstract

In this thesis we discuss a rational and data-based description of the single- and double-virutal transition form factors of the lightest pseudoscalar mesons. We obtain an accurate description of these in the spacelike and low-energy timelike regions. The phenomenological applications are wide. Among them, we discuss, the eta-eta' mixing, the rare pseudoscalar decays into a lepton pair and the pseudoscalar-pole contribution to the hadronic light-by-light part of the anomalous magnetic moment of the muon. In all these cases we discuss and illustrate the relevance of employing a data-based approach in order not to incur in potential systematic errors.