Related papers: The Supersymmetric $(B-L)$ model with three non-id…
We perform a study of the dark matter candidates of a constrained version of the minimal R-parity-conserving supersymmetric model with a gauged $U(1)_{B-L}$. It turns out that there are four additional candidates for dark matter in…
A simple model to accomodate light sterile neutrinos naturally with large mixing with the usual neutrinos has been proposed. The standard model gauge group is extended to include an $SU(2)_S$ gauge symmetry. Heavy triplet higgs scalars give…
A new mechanism for generating neutrino masses without a high-energy mass scale is proposed. The mechanism needs a fundamental mass scale M in the 100-1000 TeV region and a minimal field content beyond the Standard Model one containing a…
We extend the Type I and Type III seesaw mechanisms to generate neutrino masses within the left-right symmetric theories where parity is spontaneously broken. We construct a next to minimal left-right symmetric model where neutrino masses…
We study thermal leptogenesis in a broad class of supersymmetric SO(10) models with a left-right symmetric seesaw mechanism, taking into account flavour effects and the contribution of the next-to-lightest right-handed neutrino…
Adding right-handed neutrino singlets and/or fermion triplets to the particle content of the Standard Model allows for the implementation of the seesaw mechanism to give mass to neutrinos and, simultaneously, for the construction of…
We propose a left-right model of quarks and leptons based on the gauge group $SU(3)_C \times SU(2)_L \times SU(2)_R \times U(1)_{B-L}$, where the scalar sector consists of only two doublets: (1,2,1,1) and (1,1,2,1). As a result, any fermion…
We present the various leptogenesis scenarios which may occur if, in addition to the ordinary heavy right-handed neutrinos, there exists a heavy scalar SU(2)_L triplet coupled to leptons. We show that the contributions of the right-handed…
A full account is given of the procedure used by the authors to construct an SO(10) supersymmetric grand unified model of the fermion mass matrices. Various features of the model which gives remarkably accurate results for the quark and…
We propose a radiative lepton seesaw model with the ${\mathbb Z}_3$ Tambara-Yamagami fusion rule and gauged $B-L$ symmetry. The heavier right-handed neutral fermions ($N_R$) simultaneously contribute to the masses of charged-leptons and…
The seesaw type II mechanism is considered within the framework of a left-right chiral model with a gauge group $SU(2)_L\times SU(2)_R\times U(1)$, the lepton sector of which includes three generations of heavy Majorana neutrinos. The…
We propose a theory in which the Standard Model gauge symmetry is extended by a new $SU(2)_\ell$ group acting nontrivially on the lepton sector which is spontaneously broken at the TeV scale. Under this $SU(2)_\ell$ the ordinary leptons…
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…
In many extensions of the Standard Model, including a broad class of left-right symmetric and Grand Unified theories, the light neutrino mass matrix is given by the left-right symmetric seesaw formula $M_\nu = f v_L - \frac{v^2}{v_R} Y_\nu…
We construct an $SU(3)_L \times U(1)_N$ gauge model based on an $S_{2L}$ permutation symmetry for left-handed $\mu$ and $\tau$ families, which provides the almost maximal atmospheric neutrino mixing and the large solar neutrino mixing of…
Our present work explores the possibility of neutrino mass generation through {\em Type-I see-saw} mechanism and provides an explanation of the baryon asymmetry of the Universe via thermal leptogenesis in the framework of $Z_3$-symmetric…
The extension of the Standard model by assuming $U(1)_{\rm B-L}$ gauge symmetry is very well-motivated since it naturally explains the presence of heavy right-handed neutrinos required to account for the small active neutrino masses via the…
We show that maximal atmospheric and large solar neutrino mixing can be implemented in SU(5) gauge theories, by making use of the $U(1)_F$ symmetry associated with a suitably defined family number $F$, together with a $\mathbbm{Z}_2$…
In this article we investigate the application of complex split biquaternions and bioctonions to the standard model. We show that the Clifford algebras Cl(3) and Cl(7) can be used for making left-right symmetric fermions. Hence we…
We consider leptogenesis induced by soft supersymmetry breaking terms ("soft leptogenesis"), in the context of the inverse seesaw mechanism. In this model there are lepton number (L) conserving and L-violating soft supersymmetry-breaking…