Related papers: Dimension-five effective operators in electro-weak…
A mechanism is proposed in which a right-handed neutrino zero mode and a right-handed charged lepton zero mode can be localized at the same place along an extra compact dimension while having markedly different spreads in their wave…
Assuming the same form of all mass matrices as motivated by quark-lepton symmetry, we discuss conditions under which bi-large mixing in the lepton sector can be obtained with a minimal amount of fine tuning requirements for possible models.…
We analyze the lepton sector of a Left-Right Model based on the gauge group SU(2)_L x SU(2)_R x U(1), concentrating mainly on neutrino properties. Using the seesaw mechanism and a horizontal symmetry, we keep the right-handed symmetry…
Neutrino mass generation may affect the basic structure of the electroweak symmetry breaking sector. We consider a broad class of elementary particle theories where neutrinos get mass at a low mass scale. We show how these can be made…
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 $\mathbbm{Z}_2$…
The R-symmetry formalism is applied for the supersymmetric economical SU(3)_C X SU(3)_L X U(1)_X (3-3-1) model. The generalization of the minimal supersymmetric standard model relation among R-parity, spin and matter parity is derived, and…
Fermion masses and mixing angles including that of neutrinos are studied in a model with symmetry group SUSY $SO(10)\times \Delta (48) \times U(1)$. Universality of Yukawa coupling of superfields is assumed. The resulting texture of mass…
We propose an extension of the Standard Model by extending the EW symmetry to SU(2)_L x U(1) x Z_2 and introducing three SU(2)_L x U(1) singlet right handed neutrinos, N_R, and an additional Higgs doublet, phi. While the SM gauge bosons and…
We show that in theories that reduce, at the Fermi scale, to an extension of the standard model with two doublets, there can be additional dimension five operators giving rise to neutrino masses. In particular there exists a singlet…
We propose a model of neutrino mass matrix with large $SU(2)$ multiplets and gauged $U(1)_{L_\mu - L_\tau}$ symmetry, in which we introduce $SU(2)$ quartet scalar and quintet fermions with nonzero $L_\mu - L_\tau$ charge. Then we…
Current constraints on flavor-changing neutral currents (FCNCs) strongly indicate that any new physics emerging at the 1-10 TeV scale must adhere to the Minimal Flavor Violation (MFV) principle, where Yukawa couplings are the sole sources…
We consider the standard model extended by heavy right handed fermions transforming as triplets under SU(2)$_L$, which generate neutrino masses through the Type-III seesaw mechanism. At energies below their respective mass scales, the heavy…
We discuss neutrino masses and mixing in the framework of a supersymmetric model with an $U(1)_{R}$ symmetry, consisting of a single right handed neutrino superfield with an appropriate R charge. The lepton number ($L$) of the standard…
The strong CP problem can be solved in Parity symmetric theories with electroweak gauge group containing $SU(2)_L \times SU(2)_R$ broken by the minimal Higgs content. Neutrino masses may be explained by adding the same number of gauge…
Scalar leptoquarks naturally arise within unified theories, offering a promising avenue for addressing one of the most significant challenges of the Standard Model--the existence of non-zero neutrino masses. In this work, we present a…
Nonzero masses for the active neutrinos - regardless of their nature or origin - arise only after electroweak symmetry breaking. We discuss the parameterization of neutrino couplings to a Higgs sector consisting of one SU(2)_L scalar…
A small neutrino Majorana mass can arise in the Standard Model as an effective dimension 5 operator. We calculate the renormalization of this operator in the minimal Standard Model and in its two-Higgs-doublet and supersymmetric extensions.…
We explore alternative descriptions of the charged lepton sector in modular invariant models of lepton masses and mixing angles. In addition to the modulus, the symmetry breaking sector of our models includes ordinary flavons. Neutrino mass…
Within the framework of a local SU(3) family symmetry model, we report a general analysis of the mechanism for neutrino mass generation and mixing, including light sterile neutrinos. In this scenario, ordinary heavy fermions, top and bottom…
We propose a simple testable model with mass generation mechanisms for dark matter and neutrino based on the gauged $U(1)_{B-L}$ symmetry and an exact $Z_2$ parity. The $U(1)_{B-L}$ symmetry is spontaneously broken at the TeV scale, by…