Searching for dark sectors in multi lepton final state in e+ e- collisions

TL;DR

This paper investigates the potential to detect dark sector signals in multi-lepton final states at electron-positron colliders, focusing on the process e+e- to 3(e+e-) and its backgrounds, especially relevant for the PADME experiment.

Contribution

It provides a comparative analysis of dark Higgs mediated and Standard Model contributions to multi-lepton production in e+e- collisions, aiding dark sector searches.

Findings

Dark Higgs mediated process can be distinguished from Standard Model background.

The study highlights the importance of specific observables for dark sector detection.

Results are relevant for fixed target and low energy collider experiments, especially PADME.

Abstract

Electron positron collisions are a very promising environment to search for new physics, and in particular for dark sector related observables. The most challenging experimental problem in detecting dark sector candidates is the very high associated Standard Model background. For this reason it is important to identify observables that are, at the same time, minimally suppressed in the dark sector and highly suppressed in the Standard Model. One example is the $e^+ e^-\to 3(e^+e^-)$ process that can be mediated either by the production and subsequent decay of dark Higgs ($h'$), $e^+e^-\to A'h'\to 6e$ or produced by the Standards Model process $e^+ e^-\to 3(e^+e^-)$. In the following letter we study the relative contribution to observed $e^+ e^-\to 3(e^+e^-)$ total cross section, coming from the $h'$ mediated and from the Standard Model processes in the contest of fixed target and low energy collider experiments, with particular attention to the PADME experiment at the INFN Laboratori Nazionali di Frascati.