# Electromagnetic structure and weak decay of meson K in a light-front QCD-inspired

## TL;DR

This paper reviews the electromagnetic form factor and weak decay of the kaon using a light-front QCD-inspired model, emphasizing the importance of quark-antiquark pair contributions for covariance and matching experimental data.

## Contribution

It introduces a light-front constituent quark model that incorporates quark-antiquark pair terms to improve covariance and accurately describe kaon properties.

## Key findings

- Good agreement with experimental data for kaon weak decay constant.
- Quark-antiquark pair terms are crucial for full covariance of the electromagnetic current.
- Valence component probability of about 80% is consistent with observations.

## Abstract

The kaon electromagnetic (e.m.) form factor is reviewed considering a light-front constituent quark model. In this approach, it is discussed the relevance of the quark-antiquark pair terms for the full covariance of the e.m. current. It is also verified, by considering a QCD dynamical model, that a good agreement with experimental data can be obtained for the kaon weak decay constant once a probability of about 80% of the valence component is taken into account.