We present several interesting phenomenological implications in a model of neutrino masses which is constructed within the framework of the electroweak-scale right-handed neutrino (EW-$\nu_R$) model by applying a horizontal $A_4$ symmetry. The one-loop induced lepton flavor violating radiative decays $\mu \to e \gamma$ and $\mu$-e conversion might be related to each other under a good...
In this paper we examine the constraints dedicated LHC multi lepton searches can place on $Z'$ bosons coming from gauged muon number minus tau number, $L_{\mu}-L_{\tau}$. As the $L_{\mu}-L_{\tau}$ gauge boson does not couple to proton constituents or electrons at tree level, the current bounds are fairly loose, especially for $M_{Z'} < 1~ \rm GeV$. For $2m_{\mu} < M_{Z'} < M_Z/2$ we develop...
Leptons couple to the Higgs doublet of the standard model to acquire mass. This coupling is at tree level in the standard model, but in this talk we look at a specific model where the tree level coupling is forbidden by imposing $A_4$ symmetry. Therefore leptons couple to Higgs through a loop. As we will see in this talk, with radiative mass we can have loop contributions without the $16\pi^2$...
The LHC has reported a slight excess in the $h \to \tau \mu$ channel. If this lepton flavor violating decay is confirmed, an extension of the Standard Model (SM) will be required to explain it. A possibility to accommodate it is a model where the Higgs couples to new vectorlike fermions that in turn couple to the SM leptons through a flavor-violating four fermion interaction. The excess can be...
The Standard Model contains four accidental, or potentially emergent, global $U(1)$ symmetries. It is possible that these symmetries are indicative of a hidden gauge structure that would couple to some anomaly-free combination of the associated currents. This would result in a new Abelian gauge boson known as a $Z'$, which would be massive if the gauge-symmetry were spontaneously broken....
Observation of non-zero neutrino masses at a scale $\sim 10^{-1} - 10^{-2}$ eV is a major problem in otherwise highly successful Standard Model. The most elegant mechanism to explain such tiny neutrino masses is seesaw mechanism with right handed neutrinos. However, the required seesaw scale is so high ($\sim 10^{14}$ GeV), it will not have any direct collider implications. Recently, in our...
In this talk, we show that the model of right-handed neutrinos at the electroweak scale satisfies two important tests: the electroweak precision measurements and the 125 GeV Higgs discovery. In the model, the right-handed neutrinos along with the newly proposed mirror-charged leptons are components of $SU(2)$ doublets: $\nu_R$s here are non-sterile or fertile. The new particle content of the...
Realistic neutrino mass models often predict the existence of electroweak- and TeV-scale heavy neutrinos that couple to Standard Model particle via mixing with left-handed neutrinos. However, owing to the large differences between the neutrino mass scales investigated and QED/QCD radiation scales typical of hadron colliders, recent calculations have been plagued with soft and collinear...
