Unraveling dark Higgs mechanism via dark photon production at an e^+ e^- collider

Abstract

In the phenomenology study of dark photon, its mass origin is usually not under concern. However, in theory construction its mass is often generated via a dark Higgs mechanism, which leads to the presence of a light (non-decoupled) dark Higgs particle. In this work, we study the impact of such a dark Higgs particle in the collider detection of the dark photon. We focus on the process of final state dark photon radiating dark Higgs, which is called dark final state radiation (FSR). Considering the effects on both the signal cross section and the distribution of the missing mass square, the invisible dark photon search at BaBar is reanalyzed and a new exclusion limit for invisible dark photon is presented.