Search for type-III Seesaw heavy leptons in pp collisions at s√=8 TeV with the ATLAS Detector

FERNANDO MONTICELLI; ATLAS COLLABORATION

PHYSICAL REVIEW D

AMER PHYSICAL SOC

Lugar: New York; Año: 2015 vol. 1 p. 1 - 20

1550-7998

A search for the pair production of heavy leptons (N0,L±) predicted by the type-III seesaw theory formulated to explain the origin of small neutrino masses is presented. The decay channels N0→W±l∓ (ℓ=e,μ,τ) and L±→W±ν (ν=νe,νμ,ντ) are considered. The analysis is performed using the final state that contains two leptons (electrons or muons), two jets from a hadronically decaying W boson and large missing transverse momentum. The data used in the measurement correspond to an integrated luminosity of 20.3  fb-1 of pp collisions at s=8  TeV collected by the ATLAS detector at the LHC. No evidence of heavy lepton pair production is observed. Heavy leptons with masses below 325?540 GeV are excluded at the 95% confidence level, depending on the theoretical scenario considered.