  A search is performed for heavy resonances decaying to two long-lived massive
neutral particles, each decaying to leptons. The experimental signature is a
distinctive topology consisting of a pair of oppositely charged leptons
originating at a separated secondary vertex. Events were collected by the CMS
detector at the LHC during pp collisions at sqrt(s) = 7 TeV, and selected from
data samples corresponding to 4.1 (5.1) inverse femtobarns of integrated
luminosity in the electron (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 leptons, as a function of the long-lived massive neutral particle lifetime.
