Search for long-lived particles decaying to a pair of muons in proton-proton collisions at $\sqrt{s}=13~\mathrm{TeV}$

An inclusive search for long-lived exotic particles decaying to a pair of muons is presented. The search uses a data set collected by the CMS experiment at the LHC in proton-proton collisions at $\sqrt{s}=13~\mathrm{TeV}$ in 2016 and 2018 and corresponding to an integrated luminosity of $97.6~\mathrm{fb}^{-1}$. The experimental signature is a pair of oppositely charged muons originating from a common secondary vertex spatially separated from the proton interaction point by distances ranging from several hundred $\mu$m to several meters. The results are interpreted in the frameworks of the Hidden Abelian Higgs model, in which the Higgs boson decays to a pair of long-lived dark photons, and of a simplified model, in which long-lived particles are produced in decays of an exotic heavy neutral scalar boson.