A search is performed for a heavy resonance decaying to two long-lived massive neutral particles that each decay to a pair of muons. The process is detected experimentally via a distinct topological signature consisting of a pair of oppositely charged leptons originating at a vertex significantly displaced from the LHC beam spot. Events were collected by the CMS detector at the LHC during pp collisions at √s = 7 TeV, and selected from data samples corresponding to 5.1 fb--1 of integrated luminosity in the muon channel. No significant excess is observed above standard model expectations, and an upper limit is set with 95% confidence level on the production cross section times the branching fraction to dimuons, as a function of the long-lived massive neutral particle lifetime. |