Extending the standard model with three right-handed neutrinos (Nk) and a second Higgs doublet (Î·), odd under the discrete parity symmetry Z2, Majorana neutrino masses can be generated at 1-loopâ€¦ (More)

We analyze the importance of flavor effects in models in which leptogenesis proceeds via the decay of Majorana electroweak triplets. We find that depending on the relative strengths of gauge andâ€¦ (More)

The smallness of the observed neutrino masses might have a radiative origin. Here we revisit a specific two-loop model of neutrino mass, independently proposed by Babu and Zee. We point out thatâ€¦ (More)

We study the role played in leptogenesis by the equilibration of lepton flavors, as could be induced in supersymmetric models by off diagonal soft breaking masses for the scalar lepton doublets mÌƒÎ±Î²,â€¦ (More)

Leptoquark-Higgs interactions induce mixing between leptoquark states with different chiralities once the electro-weak symmetry is broken. In such LQ models Majorana neutrino masses are generated atâ€¦ (More)

We consider the version of the Zee model where both Higgs doublets couple to leptons. Within this framework we study charged Higgs decays. We focus on a model with minimal number of parametersâ€¦ (More)

We study variations of the standard leptogenesis scenario that can arise if an additional mass scale related to the breaking of some new symmetry (as for example a flavor or the B-L symmetry) isâ€¦ (More)

R-parity can be violated through either bilinear and/or trilinear terms in the superpotential. The decay properties of sneutrinos can be used to obtain information about the relative importance ofâ€¦ (More)

We study a model for leptogenesis in which the total CP asymmetries in the decays and scatterings involving the SU(2) singlet seesaw neutrinos NÎ± vanish (Ç«NÎ± = 0). Leptogenesis is possible due toâ€¦ (More)