Search for Light Resonances Decaying into Pairs of Muons as a Signal of New Physics The CMS Collaboration∗

A search for groups of collimated muons is performed using a data sample collected by the CMS experiment at the LHC, at a centre-of-mass energy of 7 TeV, and corre-sponding to an integrated luminosity of 35 pb−1. The analysis searches for production of new low-mass states decaying into pairs of muons and is designed to achieve high sensitivity to a broad range of models predicting leptonic jet signatures. With no ex-cess observed over the background expectation, upper limits on the production cross section times branching fraction times acceptance are set, ranging from 0.1 to 0.5 pb at the 95 % CL depending on event topology. In addition, the results are interpreted in several benchmark models in the context of supersymmetry with a new light dark sector exploring previously inaccessible parameter space. Submitted to the Journal of High Energy Physics ∗See Appendix A for the list of collaboration members a