A Parametrization for $K^+\to \pi^+\pi^- e^+\nu$

TL;DR

This paper evaluates different models and Chiral Perturbation Theory for $K_{l4}$ form factors, assessing the effectiveness of a simple parametrization in extracting experimental information.

Contribution

It introduces and tests a simple parametrization approach for $K_{l4}$ form factors to facilitate experimental data analysis.

Findings

Simple parametrization effectively captures form factor behavior.

Models and Chiral Perturbation Theory results are consistent with experimental data.

The approach simplifies the extraction of physical parameters from experiments.

Abstract

We discuss various models and Chiral Perturbation Theory results for the $K_{l4}$ form factors $F$ and $G$. We check in how much a simple parametrization with a few parameters can be used to extract information from experiment.