Neutrino Masses and Heavy Triplet Leptons at the LHC: Testability of Type III Seesaw
Jul, 2009Citations per year
Abstract: (arXiv)
We study LHC signatures of Type III seesaw in which triplet leptons are introduced to supply the heavy seesaw masses. To detect the signals of these heavy triplet leptons, one needs to understand their decays to standard model particles which depend on how light and heavy leptons mix with each other. We concentrate on the usual solutions with small light and heavy lepton mixing of order the square root of the ratio of light and heavy masses, , which could lead to a visible displaced vertex in the detector at the LHC. This fact can be used to distinguish small mixing and large mixing between light and heavy leptons. We show that, in this case, the couplings of light and heavy triplet leptons to gauge and Higgs bosons, which determining the decay widths and branching ratios, can be expressed in terms of light neutrino masses and their mixing. Using these relations, we find that there are strong correlations between neutrino mass hierarchy and the heavy triplet lepton decay patterns. If these heavy triplet leptons are below a TeV or so, it can be easily produced at the LHC due to their gauge interactions from being non-trivial representations of . We consider two ideal production channels, 1) and 2) in detail. For case 1), we find that with one or two of the light leptons being can also be effectively studied and information on neutrino mass hierarchy extracted. With judicious cuts at the LHC, the discovery of the heavy triplet leptons as high as a TeV can be achieved with 100 integrated luminosity.- 14.60.Pq
- 13.85.Qk
- lepton: triplet: decay
- neutrino: mass
- mass: hierarchy
- numerical calculations: CERN LHC Coll
- lepton: mixing angle
- heavy lepton: decay
- seesaw model
- heavy lepton: width
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