Probing Dark force at BES-III/BEPCII

TL;DR

This paper explores the potential to detect a GeV-scale dark photon at BES-III/BEPCII colliders through direct production and decay signatures, focusing on multilepton events to probe kinetic mixing parameters.

Contribution

It presents an experimental search strategy for a dark U(1) gauge boson at low-energy colliders, including analysis of Higgs'strahlung processes and multilepton signatures, extending the exploration of dark sector physics.

Findings

Dark photon production can be probed with BES-III data.

Multilepton signatures can reveal kinetic mixing parameters around 10^{-4} to 10^{-3}.

The study outlines the sensitivity of current and future data to dark sector interactions.

Abstract

We study an experimental search of a GeV scale vector boson at BES-III/BEPCII. It is responsible for mediating a new U(1)$_d$ interaction, as recently exploited in the context of weakly interacting massive particle dark matter. At low energy $e^+ e^-$ colliders this dark state can be efficiently probed. We discuss the direct productions of this light vector $U$ boson and the decay of this state with BES-III data and its foreseen larger data. In particular, we show that Higgs' strahlung in the dark sector can lead to multilepton signatures, which probe the physics range for kinetic mixing parameter $\epsilon \sim 10^{-4} -10^{-3}$ over a large portion of the parameter space.