The Non-perturbative term for the Vector Form Factor of Pion Decay

TL;DR

This paper calculates the pion decay vector form factor using a non-perturbative approach that incorporates nucleon self-energy effects, providing insights into experimental observations.

Contribution

It introduces a method to include non-perturbative effects via nucleon self-energy parameters in the calculation of the pion decay form factor.

Findings

Non-perturbative term significantly affects the form factor.

Suppression of anomalous proton interactions aligns theory with experiment.

Method improves understanding of pion decay dynamics.

Abstract

The vector form factor of the decay $\pi^{+} \rightarrow \gamma + e^{+} + \nu_e$ is calculated by the method for the pseudovector pion-nucleon system. The non-perturbative term is taken into account by using the parameter for the self-energy of nucleon following our previous calculation of the pion form factor. The suppression of the anomalous interaction of proton in the loop integral is significant to understand the experimental value.