Search for Type III Seesaw Model Heavy Fermions in Events with Four Charged Leptons using 5.8/fb of sqrt(s) = 8 TeV Data with the ATLAS Detector
https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/CONFNOTES/ATLAS-CONF-2013-019/
A search for Type III Seesaw model heavy fermions is presented. The search is performed in a data sample corresponding to 5.8 fb of integrated luminosity collected in 2012 in collisions at ~TeV by the ATLAS detector at the LHC. Charged heavy fermions, , are reconstructed in the channel together with an additional charged lepton from the decay of a partner heavy fermion, , where . No evidence of the is observed. Upper limits at 95\% confidence level are set on the production cross section of times the branching fraction to the examined four lepton final states. When interpreted in the context of the Type III Seesaw model, the results translate into a lower limit on the mass of the states of 245 GeV at 95\% confidence level.