Neutrino Mass Seesaw at the Weak Scale, the Baryon Asymmetry, and the LHC

Abstract

We consider theories where the Standard Model (SM) neutrinos acquire masses through the seesaw mechanism at the weak scale. We show that in such a scenario, the requirement that any pre-existing baryon asymmetry, regardless of its origin, not be washed out leads to correlations between the pattern of SM neutrino masses and the spectrum of new particles at the weak scale, leading to definite predictions for the LHC. For type I seesaw models with a TeV scale Z' coupled to SM neutrinos, we find that for a normal neutrino mass hierarchy, at least one of the right-handed neutrinos must be `electrophobic', decaying with a strong preference into final states with muons and tauons rather than electrons. For inverted or quasi-degenerate mass patterns, on the other hand, we find upper bounds on the mass of at least one right-handed neutrino. In particular, for an inverted mass hierarchy, this bound is 1 TeV, while the corresponding upper limit in the quasi-degenerate case is 300 GeV. Similar results hold in type III seesaw models, albeit with somewhat more stringent bounds. For the Type II seesaw case with a weak scale SU(2) triplet Higgs, we again find that an interesting range of Higgs triplet masses is disallowed by these considerations.

8 pages, 4 figures. Expanded version: two new figures, clarifications and references added; Type II seesaw case revisited. Accepted for publication in PRD

References in corpus (8)

• Leptogenesis
• Right-Handed Neutrinos at LHC and the Mechanism of Neutrino Mass Generation
• Distinguishing seesaw models at LHC with multi-lepton signals
• Neutrino Masses and the LHC: Testing Type II Seesaw
• Type-III see-saw at LHC
• Probing seesaw at LHC
• Leptogenesis beyond the limit of hierarchical heavy neutrino masses
• Testing a Neutrino Mass Generation Mechanism at the Large Hadron Collider

Cited by in corpus (11)

• Review of asymmetric dark matter
• The Phenomenology of Right Handed Neutrinos
• Testability of Type I Seesaw at the CERN LHC: Revealing the Existence of the B-L Symmetry
• Systematic approach to leptogenesis in nonequilibrium QFT: vertex contribution to the CP-violating parameter
• Systematic approach to leptogenesis in nonequilibrium QFT: self-energy contribution to the CP-violating parameter
• Probing Resonant Leptogenesis at the LHC
• Implications of Flavor Dynamics for Fermion Triplet Leptogenesis
• Flavoured CP asymmetries for type II seesaw leptogenesis
• Neutrinos with a linear seesaw mechanism in a scenario of gauged B-L symmetry
• Radiative Neutrino Mass in Type III Seesaw Model
• Hadron Collider Signatures of Lepton Number Violation in the Type II Seesaw Model