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Special Seminar | High Energy Physics Division

Search for heavy Majorana neutrinos at the CMS

HEP Special Seminar

Abstract: Nonzero mass of neutrinos established by the observation of neutrino oscillations is clear evidence of physics beyond the Standards Model ℠. The fact that neutrino masses are so much lighter than other fermion masses suggests that neutrino masses may have a different origin. The seesaw mechanism is a leading theoretical candidate which explains the origin and smallness of neutrino masses by introducing heavy Majorana neutrinos. I present searches for heavy Majorana neutrino based on the minimal Type-I seesaw model using proton-proton collision data at the LHC.

In addition, the SM does not provide any clear answer concerning parity violation in the weak sector or matter dominance of the universe. One of the leading theoretical solutions is to introduce a left-right symmetry model (LRSM). In this model, there are three additional gauge bosons, {W}_{R}^{+-} and Z’, as well as three right-handed neutrinos ({N}_{e}, {N}_{mu}, and {N}_{tau}). The spontaneous symmetry breaking of the LRSM, at some high energy scale, reproduces the gauge group of the SM where parity violation is naturally embedded. As a consequence, the seesaw mechanism is naturally embedded with heavy right-handed neutrinos and light left-handed neutrinos. I present a search for pair production of heavy Majorana neutrinos from Z’ decays using proton-proton collision data at LHC.