Related papers: Dirac Vs. Majorana Neutrino Masses From a TeV Inte…
We describe a class of supersymmetric models in which neutrinos are kept light by an R-symmetry. In supergravity, R-symmetry must be broken to allow for a small cosmological constant after supersymmetry breaking. In the class of models…
We consider a model with three right-handed neutrinos in which Yukawa coupling constants and Majorana masses are obtained by requiring the modular $A_4$ symmetry. It has been shown that the model can explain mass hierarchies and mixing…
The existence of a neutrino magnetic moment implies contributions to the neutrino mass via radiative corrections. We derive model-independent "naturalness" upper bounds on the magnetic moments of Dirac and Majorana neutrinos, generated by…
We entertain the possibility that neutrino masses and dark matter (DM) originate from a common composite dark sector. A minimal effective theory can be constructed based on a dark $SU(3)_D$ interaction with three flavors of massless dark…
Majorana masses of the neutrino implies lepton number violation and is intimately related to the lepton asymmetry of the universe, which gets related to the baryon asymmetry of the universe in the presence of the sphalerons during the…
In Neutrinophilic Two Higgs Doublet Models, Dirac neutrino masses are obtained by forbidding a Majorana mass term for the right-handed neutrinos via a symmetry. We study a variation of such models in which that symmetry is taken to be a…
The thermodynamic equations of state for Majorana and Dirac fermions are quite different even in the limit of zero mass. The corresponding equations are derived from general principles, and then applied to neutrinos. The nature of the…
During a large period of time, the anomalous baryon number violating interactions are in equilibrium, when the $(B+L)$ asymmetry is washed out. If there is any lepton number violation during this period, that will also erase the $(B-L)$…
The most plausible see-saw explanation of the smallness of the neutrino masses is based on the assumption that total lepton number is violated at a large scale and neutrinos with definite masses are Majorana particles. In this review we…
Symmetry-based ideas, such as the quark-lepton complementarity (QLC) principle and the tri-bimaximal mixing (TBM) scheme, have been proposed to explain the observed mixing pattern of neutrinos. We argue that such symmetry relations need to…
We propose a new gauged $B-L$ extension of the standard model where light neutrinos are of Dirac type, naturally acquiring sub-eV mass after electroweak symmetry breaking, without any additional global symmetries. This is realised by…
We discuss the necessity of a right-handed Weyl neutrino due to the vector-like phenomenon of the regularized Standard Model. It is shown that this right-handed neutrino is decoupled from low energies as a free particle, and Dirac neutrino…
The ansatz that the right-handed neutrino fields are real spinors is proposed in this letter. We naturally explain why the right-handed neutrinos don't feel the electroweak interactions and why there is neutrino mixing. It is found that the…
We derive the neutrino oscillation probabilities including sterile neutrinos by using the Dirac equation. If neutrinos have both the Dirac and the Majorana mass terms, left-handed neutrino $\nu_L$ and right-handed anti-neutrino $\nu_R^c$…
We evaluate the predictions of the left-right symmetry model based on $SU(2)\otimes U(1)$ gauge group with one bidoublet and one doublet Higgs fields on the parity violation, charged leptons and neutrinos masses. Parity violation in the…
We investigate left-right symmetric extensions of the standard model based on open strings ending on D-branes, with gauge bosons due to strings attached to stacks of D-branes and chiral matter due to strings stretching between intersecting…
We consider an extension of the Standard Model with three right-handed (RH) neutrinos and a Dirac pair of extra sterile neutrinos, odd under a discrete $Z_2$ symmetry, in order to have left-right symmetry in the neutrino content and obtain…
There are good reasons why neutrinos could be Majorana particles, but there exist also a number of very good reasons why neutrinos could have Dirac masses. The latter option deserves more attention and we derive therefore analytic…
A Majorana mass term for the $\tau$ neutrino would induce neutrino - antineutrino mixing and thereby a process which violates fermion number by two units. We study the possibility of distinguishing between a massive Majorana and a Dirac…
We propose novel tree level seesaw mechanism with TeV-scale vectorlike Dirac mediators that produce Majorana masses of the known neutrinos. The gauge quantum number assignment to the Dirac mediators allows them to belong to a weak triplet…