Related papers: Undemocratic Dirac seesaw
Light Dirac neutrino of mass of mass of the order of few eV is obtained in an $SU(2)_L\times U(1)_Y$ model with an extended Higgs sector and right-handed neutrinos. Small neutrino mass is generated at the tree level through small effective…
We investigate a novel scenario involving asymmetric keV-range dark matter (DM) in the form of right-handed (sterile) neutrinos. Based on the Fermi-Dirac distribution, we demonstrate that asymmetric fermionic DM forms a Fermi degenerate…
We discuss asymmetric or symmetric dark matter candidate in the supersymmetric Dirac leptogenesis scenario. By introducing a singlet superfield coupling to right-handed neutrinos, the overabundance problem of dark matter can be evaded and…
We propose to relate dark matter stability to the possible Dirac nature of neutrinos. The idea is illustrated in a simple scheme where small Dirac neutrino masses arise from a type-I seesaw mechanism as a result of a $Z_4$ discrete lepton…
We suggest that many of the free parameters in the supersymmetric extensions of the Standard Model can be all linked together to the existence of a non universal U(1) gauge symmetry, which has been spontaneously broken at very high scale.…
If neutrinos are Dirac particles the existence of light right-handed neutrinos $\nu_{R}$ is implied. Those would contribute to the effective number of relativistic neutrino species $N_{{\rm eff}}$ in the early Universe. With pure standard…
We propose a gauged $U(1)_{B-L}$ extension of the standard model (SM) to explain simultaneously the light neutrino masses and dark matter (DM). The generation of neutrino masses occurs through a variant of type-II seesaw mechanism in which…
Seesaw mechanism appears to be the simplest and most appealing way to understand small neutrino masses observed in recent experiments. It introduces three right handed neutrinos with heavy masses to the standard model, with at least one…
We propose a $B-L$ gauged extension of the Standard Model where light neutrino masses arise from type III seesaw mechanism. Unlike the minimal $B-L$ model with three right handed neutrinos having unit lepton number each, the model with…
A solution for the neutrino mass and mixing pattern is proposed which is compatible with all available experimental data on neutrino oscillations. This solution involves Majorana neutrinos of the pseudo-Dirac type, i.e. m_Majorana <<…
We propose a new seesaw model in an extra-dimensional setup where only right-handed neutrinos are bulk fields. In the model, localizations of an extra-dimensional wave function and brane Majorana mass of the right-handed neutrinos can be…
We point out that the minimal seesaw model can provide a natural framework to accommodate tiny neutrino masses, while its experimental testability and notable predictiveness are still maintained. This possibility is based on the observation…
We present the signatures and prospects for the indirect detection of a Dirac right-handed neutrino dark matter candidate in neutrino telescopes, cosmic positron experiments and gamma-ray telescopes. An example of such a dark matter…
We show that under a new U(1) gauge symmetry, which is non-anomalous in the presence of one ``right-handed neutrino'' per generation and consistent with the standard model Yukawa couplings, the most general fermion charges are determined in…
Neutrinos are the only particles in the Standard Model of particle physics that have only been observed with left handed chirality to date. If right handed neutrinos exist, they could be responsible for several phenomena that have no…
If neutrinos are Dirac particles, their right-handed partners must be present in the theory. Once introduced in the Standard Model (SM), the difference between the baryon number $B$ and the lepton number $L$ can be promoted to a local…
We study a mechanism where tiny neutrino masses arise only from radiative contribution in a supersymmetric model. In each generation, the tree-level light neutrino mass is rotated away by introducing a second SM singlet $s_{L}$ that forms a…
The gauged $B - L$ symmetry is one of the simplest and well studied extension of standard model. In the conventional case, addition of three singlet right handed neutrinos each transforming as $-1$ under the $B - L$ symmetry renders it…
In a bid to simultaneous explanation of dark matter (DM) and tiny but non-zero masses of left-handed neutrinos, we propose a minimal extension of the Standard Model (SM) by a vector-like fermion doublet and three right handed (RH) singlet…
In the first part of this talk it is discussed why observed neutrino oscillations (which suggest the existence of right-handed neutrinos with certain Dirac and Majorana masses) seem to select out the route to higher unification based on the…