Search for dark photons decaying to lepton jets at CMS

Production of dark photons with GeV-scale mass is predicted in many dark sector models. A distinctive signature is the presence of pairs of oppositely charged leptons (muons only, in this study) where the angle between the leptons in a pair is small so that they form a lepton jet. We present preliminary studies for the sensitivity of a model-independent search for prompt dark photons at Run 2 of the CMS experiment. This update includes event selection and the use of a boosted decision tree to identify lepton jets from dark photons.