Related papers: A viable $L_e-L_\mu$ model with $\mu\to e$ violati…
The fact that neutrinos are massive indicates that the Standard Model (SM) requires extension. We propose a low energy (<TeV) B-L extension of the SM, which is based on the gauge group SU(3)_C x SU(2)_L x U(1)_Y x U(1)_{B-L}. We show that…
We investigate a variant of Left-Right symmetric model based on $E_6$ inspired $SU(3)_C \otimes SU(2)_L \otimes U(1)_L \otimes SU(2)_R \otimes U(1)_R$ gauge group $(32121)$. Spontaneous breaking of $32121$ down to the Standard Model (SM)…
A model of a light $Z'$ boson based on gauged $L_\mu - L_\tau$ $U(1)$ symmetry is constructed. The $Z'$ boson mass is constrained to be in the range of 0.8 to 1 GeV from Z and $Z'$ mass relation, g-2 of muon, and tau decays. The two body…
We propose models for neutrino masses and mixing in the framework of low scale $U(1)_{L_\mu-L_\tau}$ gauge extension of the standard model. The models are designed to spontaneously break $U(1)_{L_\mu-L_\tau}$ so that the…
We consider a gauged $U(1)_{L_\mu-L_\tau}$ extension of the left-right symmetric theory in order to simultaneously explain neutrino mass, mixing and the muon anomalous magnetic moment. We get sizeable contribution from the interaction of…
A possible extension of the Standard Model to include lepton number as local gauge symmetry is investigated. In such a model, anomalies are canceled by two extra fermions doublet. After leptonic gauge symmetry spontaneously broken, three…
Secret coupling of neutrinos to a new light vector boson, $Z'$, with a mass smaller than 100 MeV is motivated within a myriad of scenarios which are designed to explain various anomalies in particle physics and cosmology. Due to the…
We explore the potential for detecting the inelastic dark model (DM) with an additional $U(1)_D$ gauge symmetry at various types of lepton colliders. The new gauge boson $Z'$ resulting from the spontaneous breaking of $U(1)_D$ can act as a…
In this work, we study an extension of the Standard Model (SM) based on the gauge symmetry $SU(3)_C\times SU(2)_L\times U(1)_{Y'}\times U(1)_R$ where only the right-handed fermions have nonzero $U(1)_R$ charge and the $U(1)_Y$ weak…
We consider experimental constraints in the MeV region in order to determine the parameter space for the $U(1)_X$ extension of the Standard Model, presented in the first part of our work. In particular, we focus on the model UV-completed by…
An electroweak model of SU(3) $\times$ U(1) gauge group is studied. {}From the group theoretical constraint, the symmetry breaking of this model to the standard model occurs at 1.7~TeV or lower. Hence the mass of the new neutral gauge boson…
Supersymmetric B-L extension of the Standard Model (SM) is one of the best candidate for physics beyond the SM that accounts for TeV scale seesaw mechanism and provides an attractive solution for the Higgs naturalness problem. We analyze…
Adding a second scalar doublet (eta^+,eta^0) and three neutral singlet fermions N_{1,2,3} to the Standard Model of particle interactions with a new Z_2 symmetry, it has been shown that Re(eta^0) or Im(eta^0) is a good dark-matter candidate…
We study the \mu \to e \gamma decay in the Z_3-invariant next-to-minimal supersymmetric (SUSY) Standard Model (NMSSM) with superheavy right-handed neutrinos. We assume that the soft SUSY breaking parameters are generated at the GUT scale,…
We study the one-loop induced muon number processes when the standard model is minimally extended to include a $\rm SU(2)$ singlet of a charged scalar $h^+$ and a neutral fermion $N$. We find that $\mu \rightarrow e \gamma$ is more…
According to Sumino's idea, a family U(3) gauge symmetry is assumed. SU(2)$_L$ doublet fields $q_L$ and $\ell_L$ are assigned to {\bf 3} of U(3), while singlets $u_R$, $d_R$, $e_R$ and $\nu_R$ are assigned to {\bf 3$^*$} of U(3). Then,…
Standard Model may be defined with the additional discrete symmetry, i.e. with the gauge group $SU(3)\times SU(2) \times U(1)/{\cal Z}$ (${\cal Z} = Z_6$, $Z_3$ or $Z_2$) instead of the usual $SU(3)\times SU(2) \times U(1)$. It has the same…
Upcoming experiments will improve the reach for the lepton flavour violating (LFV) processes $\mu \to e \gamma$, $\mu \to e \bar{e} e$ and $\mu A \to e A$ by orders of magnitude. We investigate whether this upcoming data could rule out some…
We consider a new massive vector-boson Z' that couples to leptons through the L_mu - L_tau current, and to quarks through an arbitrary set of couplings. We show that such a model can be obtained from a renormalizable field theory involving…
We propose a new $\mathrm{SU}(3)_C \otimes \mathrm{SU}(2)_{L}\otimes \mathrm{U}(1)_{Y}\otimes \mathrm{U}(1)_{X}$ gauge model which is non universal respect to the three fermion families of the Standard Model. We introduce additional one…