Related papers: Dirac Leptogenesis in extended nMSSM
We discuss two extensions of the Standard Model based on the seesaw mechanism and on non-abelian family symmetry groups O(2) and $D_4$, respectively. Both models have a twofold-degenerate neutrino Dirac mass matrix $M_D$, a Majorana mass…
Models of type I seesaw can be implemented at the electroweak scale in a natural way provided that the heavy neutrino singlets are quasi-Dirac particles. In such case, their contribution to light neutrino masses has the suppression of a…
We explore how the seesaw sector in neutrino mass models may be constrained through symmetries to be completely determined in terms of low-energy mass, mixing angle and CP-violating phase observables. The key ingredients are intra-family…
Supersymmetric scenarios incorporating thermal leptogenesis as the origin of the observed matter-antimatter asymmetry generically predict abundances of the primordial elements which are in conflict with observations. In this paper we…
We make an analytic and numerical study of leptogenesis in the framework of the (Supersymmetric) Standard Model plus the see-saw mechanism with a U(1) family symmetry and single right-handed neutrino dominance. In presenting our analytic…
A new approach for deriving neutrino masses from the known masses of quarks, charged leptons, and the parameters of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix is proposed. This framework is based on the simultaneous diagonalization…
The nearly Minimal Supersymmetric Standard Model (nMSSM) is one of the promising models of the new physics, since this model can avoid hierarchy problem, mu problem, cosmological domain wall problem, and tadpole problem simultaneously. In…
In a simple extension of the standard model (SM), a pair of vector like lepton doublets ($L_1$ and $L_2$) and a $SU(2)_L$ scalar doublet ($\eta$) have been introduced to help in accommodating the discrepancy in determination of the…
The standard model left-handed neutrinos and several right-handed neutrinos can obtain a tiny Dirac mass matrix through their mixings with relatively heavy Dirac fermions. In this Dirac seesaw scenario, the mixings involving the left-handed…
The Standard Model (SM) of particle physics is a precise model of electroweak interactions, however there is growing tension between the SM and observations (neutrino oscillations, dark matter, dark energy, baryogenesis, among others).…
The family of Dirac Seesaw models offers an intriguing alternative explanation for the smallness of neutrino masses without necessarily requiring microscopic lepton number violation, when compared to the more familiar class of Majorana…
The Dirac Scotogenic model provides an elegant mechanism for generating small Dirac neutrino masses at the one-loop level. A single abelian discrete $Z_{6}$ symmetry simultaneously protects the ``Diracness'' of the neutrinos and the…
Assuming a type-I seesaw mechanism for neutrino mass generation and invoking a baryogengesis via leptogenesis scenario, we consider a reasonable hierarchical structure for Dirac neutrino mass matrix, similar to up-type quark mass matrix.…
We study sterile neutrino dark matter in a minimal Type-I Dirac seesaw framework where the states responsible for generating Dirac neutrino masses at tree level can be viable dark matter candidates. A $\mathcal{Z}_6$ symmetry, spontaneously…
We consider an extension of the standard electroweak model with three Higgs doublets and global $B-L$ and $\mathbb{Z}_2$ symmetries. Two of the scalar doublets are inert due to the $\mathbb{Z}_2$ symmetry. We calculated all the mass spectra…
Alternatives to the see-saw mechanism are explored in supersymmetric models with three right-handed or sterile neutrinos. Tree-level Yukawa couplings can be drastically suppressed in a natural way to give sub-eV Dirac neutrino masses. If,…
We provide a framework for quasi-degenerate neutrinos consistent with a successful leptogenesis, based on the L_mu-L_tau flavor symmetry and its breaking pattern. In this scheme, a fine-tuning is needed to arrange the small solar neutrino…
Leptogenesis typically requires the introduction of heavy particles whose out-of-equilibrium decays are essential for generating a matter-antimatter asymmetry, according to one of Sakharov's conditions. We demonstrate that in Dirac…
We propose a model with one large submm size extra dimension in which the gravity and right-handed (RH) neutrino propagate, but the three Standard Model (SM) families are confined to fat branes of TeV^(-1) size or smaller. The charged…
We construct an explicit model implementing electromagnetic leptogenesis. In a simple extension of the Standard Model, a discrete symmetry forbids the usual decays of the right-handed neutrinos, while allowing for an effective coupling…