Search for long-lived particles decaying to leptons with large impact parameter in proton-proton collisions at s = 13 Te

Abstract

A search for new long-lived particles decaying to leptons using proton-proton collision data produced by the CERN LHC at $\sqrt{s}=13\text{Te}$ is presented. Events are selected with two leptons (an electron and a muon, two electrons, or two muons) that both have transverse impact parameter values between 0.01 and 10 $\text{cm}$ and are not required to form a common vertex. Data used for the analysis were collected with the CMS detector in 2016, 2017, and 2018, and correspond to an integrated luminosity of 118 (113) ${\text{fb}}^{-1}$ in the $e_{}^{}{e}_{}^{}$ channel ( $e_{}^{}\mu$ and $\mu \mu$ channels). The search is designed to be sensitive to a wide range of models with displaced $e_{}^{}\mu$ , $e_{}^{}{e}_{}^{}$ , and $\mu \mu$ final states. The results constrain several well-motivated models involving new long-lived particles that decay to displaced leptons. For some areas of the available phase space, these are the most stringent constraints to date.