  A search is presented in proton-proton collisions at sqrt(s) = 7 TeV for
fermionic triplet states expected in type III seesaw models. The search is
performed using final states with three isolated charged leptons and an
imbalance in transverse momentum. The data, collected with the CMS detector at
the LHC, correspond to an integrated luminosity of 4.9 inverse femtobarns. No
excess of events is observed above the background predicted by the standard
model, and the results are interpreted in terms of limits on production cross
sections and masses of the heavy partners of the neutrinos in type III seesaw
models. Depending on the considered scenarios, lower limits are obtained on the
mass of the heavy partner of the neutrino that range from 180 to 210 GeV. These
are the first limits on the production of type III seesaw fermionic triplet
states reported by an experiment at the LHC.

High Energy Physics - Experiment