Dark Photons from displaced vertices

Abstract: We investigate the unexplored regions of the dark photon parameter space to find a search strategy suitable to probe these. We show how displaced track searches at colliders with large 4pi trackers around the interaction point are excellent choices for exploring these uncharted regions. As an example, we study in detail the sensitivity of the Belle II trackers to dark photons which mediate interactions between the visible and dark sectors. We also show that the same strategy can be employed by other experiments to achieve the same goal.