Related papers: Minimal Dirac seesaw accompanied by Dirac fermioni…
A Dirac fermion carrying an integral weak isospin and the vanishing hypercharge is considered as its neutral component can be a promising dark matter candidate (called the minimal dark matter) whose mass is of order 100 GeV. While the…
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…
We study neutrino mass generation and dark matter in a left-right symmetric model. The model is based on an $SU(3)_c\times SU(2)_L \times SU(2)_R \times U(1)_{B-L}$ gauge theory with a softly broken parity symmetry. Masses of the charged…
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.…
New models have recently been proposed in which a second Higgs doublet couples only to the lepton doublets and right-handed neutrinos, yielding Dirac neutrino masses. The vacuum value of this second "nu-Higgs" doublet is made very small by…
We propose a novel cogenesis framework based on the type-I Dirac seesaw mechanism. The minimal type-I Dirac seesaw with three heavy vector like fermions $(N)$, one singlet scalar $(\eta)$ and the right-handed counterparts $(\nu_R)$ of the…
In the conventional gauged ${B-L}$ extension of the standard model, the $B-L$ charge of the singlet scalar $\chi$, responsible for the breaking of $U(1)_{B-L}$ symmetry, is taken to be 2 such that it can anchor type-I seesaw by giving…
We investigate a $U(1)_{B-L}$ gauge extension of the Standard Model (SM) where the gauge boson mass is generated by the Stueckelberg mechanism. Three right-handed neutrinos are added to cancel the gauge anomaly and hence the neutrino masses…
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…
We introduce the "Dirac similarity principle" that states that only those point-like Dirac particles which can interact with the Dirac electron can be observed, such as in the Standard Model. We emphasize that the existing world of the…
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 propose a new mechanism to generate minuscule active neutrino masses in a five-dimensional~(5d) spacetime of an interval without introducing $SU(2)_L$ singlet neutrinos. Under asymmetric boundary conditions on the two end points, a bulk…
We consider a simple model of a dark sector with a chiral $U(1)$ gauge symmetry. The anomaly-free condition requires at least five chiral fermions. Some of the fermions acquire masses through a vacuum expectation value of a Higgs field, and…
We study a different variant of Left-Right Symmetric Model, incorporating Dirac type neutrinos. In the absence of the bi-doublet scalars, the possibility of a universal seesaw type of mass generation mechanism for all the Standard Model…
We examine simple extension of the standard model with a pair of fermions, one singlet and a doublet, in a common thread linking the dark matter problem with the smallness of neutrino masses associated with several exciting features. In the…
The usual see-saw formula is modified by the presence of two Higgs triplets in left-right symmetric theories. The contribution from the left-handed Higgs triplet to the see-saw formula can dominate over the conventional one when the…
Recently, there has been a growing interest in extensions of the Standard Model in which naturally small Dirac neutrino masses arise due to existence of a symmetry which protects neutrino's Diracness. Motivated by this, we consider an…
The radiative type-I seesaw has been already implemented to explain the lightness of Majorana neutrinos with both Majorana and Dirac heavy fermions, and the lightness of Dirac neutrinos with Dirac heavy fermions. In this work we present a…
We propose a minimal extension of the standard model with U(1)_{B-L} \times Z_{2} symmetry. In this model by assuming that the neutrinos are Dirac (i.e. $B-L$ is an exact symmetry), we found a simultaneous solution for non zero neutrino…
If neutrinos are Dirac fermions, certain new physics beyond the standard model should exist to account for the smallness of neutrino mass. With two additional scalars and a heavy intermediate fermion, in this paper, we systematically study…