Dilepton Signal of a Type-II Seesaw at CERN LHC: Reveals a TeV Scale B-L Symmetry

Abstract

We explore the discovery potential of doubly charged Higgs bosons (\xi^{\pm\pm}) at the CERN Large Hadron Collider (LHC). For moderate values of the coupling constants in the original Type-II seesaw model, these doubly-charged Higgs bosons are not accessible by any present or near future collider experiments. In a gauged B-L symmetric model we introduce two triplet scalars to execute a variant of type-II seesaw at the TeV scale. This leads to a clear like-sign dilepton signal in the decay mode of \xi^{\pm\pm} for a small vacuum expectation value (\lsim 10^5 \eV) of the triplet scalar \xi= (\xi^{++}, \xi^+, \xi^0) of mass \lsim 1 \TeV. To be specific, for a mass range of 200-1000 GeV of \xi^{\pm\pm}, the like-sign dilepton signal can be detected at CERN LHC at a center of mass energy 14 TeV with an integrated luminosity > 30 {\rm fb}^{-1}. The same analysis is also pursued with center of mass energies 7 TeV and 10 TeV as well. We also comment on the decay mode of singly charged scalars and neutral B-L gauge boson in this model.

Comments: Minor change in Introduction, Z' contribution to the production of doubly charged scalars are explicitly shown, new figures added, new references added. To appear in Physical Review D