A Search for Beyond Standard Model Light Bosons Decaying into Muon Pairs

A dataset corresponding to $2.8~\mathrm{fb}^{-1}$ of proton-proton collisions at $\sqrt{s} = 13~\mathrm{TeV}$ was recorded by the CMS experiment at the CERN LHC. These data are used to search for new light bosons with a mass in the range $0.25-8.5~\mathrm{GeV}/c^2$ decaying into muon pairs. No excess is observed in the data, and a model-independent upper limit on the product of the cross section, branching fraction and acceptance is derived. The results are interpreted in the context of two benchmark models, namely, the next-to-minimal supersymmetric standard model, and dark SUSY models including those predicting a non-negligible light boson lifetime.