Type II leptogenesis and the neutrino mass scale

By S. Antusch, S. King. 2004

155 citations recorded by the source corpus.

We discuss the effect of the neutrino mass scale on baryogenesis via the out-of-equilibrium decay of the lightest right-handed (s)neutrinos in type II see–saw models. We calculate the type II contributions to the decay asymmetries for minimal scenarios based on the Standard Model and on the Minimal Supersymmetric Standard Model, where the additional direct mass term for the neutrinos arises from a Higgs triplet vacuum expectation value. The result in the supersymmetric case is new and we correct the previous result in the scenario based on the Standard Model. We confirm and generalize our results by calculating the decay asymmetries in an effective approach, which is independent of the realization of the type II contribution. We derive a general upper bound on the decay asymmetry in type II see–saw models and find that it increases with the neutrino mass scale, in sharp contrast to the type I case which leads to an upper bound of about 0.1 eV on the neutrino mass scale. We find a lower bound on the mass of the lightest right-handed neutrino, significantly below the corresponding type I bound for partially degenerate neutrinos. This lower bound decreases with increasing neutrino mass scale, making leptogenesis more consistent with the gravitino constraints in supersymmetric models.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/d46ec2d0fea210fe6006f518c1ae460e91376afb

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In Nuclear and High Energy Physics

1. E. Nardi
2. D. Bodeker
3. W. Buchmuller
4. C. S. Fong
5. A. Riotto
6. R. Mohapatra
7. H. An
8. Yue Zhang

Citations in the corpus

• Running neutrino mass parameters in see-saw scenarios (2005, unknown): “In the case of a type II seesaw and for M1 ¿ M∆, where M∆ is the mass of the SU(2)L-triplet Higgs, the decay asymmetry for type II leptogenesis via the lightest right-handed neutrino coincides with the result for the conventional see-saw [64].”
• Flavor structures of charged fermions and massive neutrinos (2019, unknown): “6(b) can be replaced by ∆) [942, 943, 944].”
• Leptogenesis in the Universe (2012, background): “nism necessarily involves lepton number violation and allows for new CP-violating phases, it is interesting to examine it in the 41 Neutrino Physics Leptogenesis in the Universe light of leptogenesis [212, 213, 214, 215, 216, 180, 217, 218, 219, 185, 220, 221, 222, 223, 224, 81, 225, 226, 227, 228, ”
• Leptogenesis as a common origin for matter and dark matter (2009, background): “However, in the latter case, the triplet Higgs contribution dominates the leptogenesis in the dark sector [60, 61 ] which will ruin the relation nB = nB′.”
• Baryogenesis from the weak scale to the grand unification scale (2020, methodology): “In type-II models, where a triplet contribution appears in the neutrino mass matrix as in left-right symmetric models, the direct connection between neutrino masses and leptogenesis is lost (Hambye and Senjanovic, 2004; Antusch and King, 2004).”