Study of $\pi^{0}$ and $\eta$ decays containing dilepton

TL;DR

This paper calculates form factors for pseudoscalar meson decays involving dileptons using a light-front quark model, and compares the decay predictions with experimental data, notably for the $ ext{pi}^0 o e^+ e^-$ decay.

Contribution

It provides a detailed calculation of momentum-dependent form factors for $ ext{pi}^0$ and $ ext{eta}$ decays within the light-front quark model, offering new theoretical predictions.

Findings

Decay branching ratio for $ ext{pi}^0 o e^+ e^-$ is $6.68 imes 10^{-8}$

Results are consistent with recent experimental measurements

Provides form factors for various dilepton decay channels

Abstract

We calculate the momentum dependent form factors of $P \to \gamma^* \gamma^*$($P=\pi^{0}, \eta$) within the light-front quark model. Using the form factors, we examine the decays of $P \to l^+ l^-$, $P \to l^+ l^- \gamma$ and $P \to l^+ l^- l^+ l^-$($l=e$ or $\mu$) and compare our results with the experimental data and other theoretical predictions. In particular, for $\pi^0 \to e^+e^-$, we find that the decay branching ratio is $6.68\times 10^{-8}$, which is consistent with the recent measurement of $(7.48\pm0.29\pm0.25)\times 10^{-8}$ by E799 of KTeV/Fermilab.