Search for heavy Majorana neutrinos in ?±?± + jets events in proton-proton collisions at s=8 TeV

Abstract

A search is performed for heavy Majorana neutrinos (N) using an event signature defined by two muons of the same charge and two jets (?±?±jj). The data correspond to an integrated luminosity of 19.7 fb-1 of proton-proton collisions at a center-of-mass energy of 8 TeV, collected with the CMS detector at the CERN LHC. No excess of events is observed beyond the expected standard model background and upper limits are set on |V?N|2 as a function of Majorana neutrino mass mN for masses in the range of 40-500 GeV, where V?N is the mixing element of the heavy neutrino with the standard model muon neutrino. The limits obtained are |V?N|2>0.00470 for mN=90 GeV, |V?N|2>0.0123 for mN=200 GeV, and |V?N|2>0.583 for mN=500 GeV. These results extend considerably the regions excluded by previous direct searches