Phenomenology of a Born-Infeld extension of the $U(1)_{\rm Y}$ sector at lepton colliders

TL;DR

This paper explores a non-linear extension of the hypercharge sector in the Standard Model, predicting new interactions among neutral gauge bosons and assessing their detectability at future lepton colliders.

Contribution

It introduces a Born-Infeld type extension of the $U(1)_Y$ sector, leading to novel quartic gauge interactions and analyzes their experimental implications.

Findings

Current data do not constrain the model's mass parameter.

Future colliders could exclude $oxed{eta} \, \lesssim \, m_Z$ with improved statistics.

The model's predictions relate to recent studies on anomalous gauge couplings.

Abstract

In this work we perform a non-linear extension of the $U(1)_{\rm Y}$ sector of the Standard Model leading to novel quartic effective interactions between the neutral gauge bosons. We study the induced effects through high-energy processes resulting in three photons, namely, Z-boson decay and electron-positron annihilation. Available experimental data on these processes do not yield viable lower bounds on the mass parameter $\sqrt{\beta}$, but we estimate that the range $\sqrt{\beta} \lesssim m_Z$ could be reliably excluded with better statistics in future $e^- e^+$ colliders. We also discuss neutral gauge-boson scatterings, contextualizing our findings with recent results on anomalous quartic gauge couplings.