engleski

Exotic Seesaw-Motivated Heavy Leptons at the LHC

In a model with vectorlike lepton SU(2)_L 5-plet and two scalar quadruplets neutrino masses arise from a dimension nine operator. The new seesaw formula m_nu ~ v^6/M^5 and the empirical masses m_nu ~ 10^-1 eV give M < TeV for the new states. We show that the Drell-Yan production and the decays of TeV-scale 5-plet leptons are testable at the LHC. At the present LHC \sqrt{;s}; = 7 TeV, total production cross section for Sigma - \bar{;Sigma}; pairs is 270 fb for M_Sigma = 400 GeV. Besides producing same-sign dilepton events, they could lead to decays Sigma^{;+++}; -> W^+ W^+ l^+ with a specific decay signature.

neutrino mass; seesaw; exotic fermions

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