Muon g-2, rare decays P \to l^+l^- and transition form factors P \to \gamma\gamma^*

TL;DR

This paper discusses the importance of transition form factors in light pseudoscalar mesons for testing the standard model, especially in relation to muon g-2 and rare meson decays, and examines recent BABAR data at high momentum transfer.

Contribution

It analyzes the consistency of BABAR's new form factor data with perturbative QCD predictions, highlighting implications for theoretical uncertainties.

Findings

BABAR data at large momentum transfer challenges perturbative QCD expectations

Theoretical uncertainties in standard model predictions are influenced by form factor behavior

Discussion on the potential need for revised models or interpretations

Abstract

Measuring the muon anomalous magnetic moment g-2 and the rare decays of light pseudoscalar mesons into lepton pair P \to l+l- serve as important test of the standard model. To reduce the theoretical uncertainty in the standard model predictions the data on the transition form factors of light pseudoscalar mesons play significant role. Recently new data on behavior of these form factors at large momentum transfer was supplied by the BABAR collaboration. We comment on the (in)consistency of these data with perturbative QCD expectation.