Search for dark Higgsstrahlung in e+ e- -> mu+ mu- and missing energy events with the KLOE experiment

TL;DR

This study searched for signs of a dark Higgs boson produced alongside a dark photon in electron-positron collisions, but found no evidence and set limits on the process's parameters.

Contribution

First search for dark Higgsstrahlung in e+ e- collisions with the KLOE detector, establishing new upper limits on the process parameters.

Findings

No evidence of the dark Higgsstrahlung process was observed.

Upper limits were set on the coupling parameters within the explored mass range.

Constraints were placed on the masses of the dark photon and dark Higgs boson.

Abstract

We searched for evidence of a Higgsstrahlung process in a secluded sector, leading to a final state with a dark photon U and a dark Higgs boson h', with the KLOE detector at DAFNE. We investigated the case of h' lighter than U, with U decaying into a muon pair and h' producing a missing energy signature. We found no evidence of the process and set upper limits to its parameters in the range 2m_mu<m_U<1000 MeV, m_h'<m_U.