Search for long-lived particles that decay into final states containing two muons, reconstructed using only the CMS muon chambers

A search is performed for long-lived neutral particles that decay into final states that include a pair of muons. These are reconstructed using only the CMS muon chambers. The experimental signature is a distinctive topology consisting of a pair of muons originating from a displaced secondary vertex. Events corresponding to an integrated luminosity of 20.5 fb$^{-1}$ were collected with the CMS detector at the CERN LHC in pp collisions at $\sqrt{s} = 8$ TeV. No significant excess is observed above standard model expectations. Upper limits on the product of the cross section and branching fraction of such a signal are presented as a function of the long-lived particle's mean proper decay length. The limits are provided for two specific models. In the first model, a Higgs boson decays into a pair of long-lived, neutral bosons, each of which can decay into a pair of muons. In the second model, squarks are pair produced and the decay of each produces a long-lived neutralino that subsequently decays to two muons and a neutrino. The limits are also presented in an approximately model-independent way, allowing them to be applied to a wide class of models yielding the above topology. A combination of these limits with those from a related search that used muons reconstructed in the CMS silicon tracker is also presented.