Related papers: Fourth Generation Leptons and Muon $g-2$
We construct a novel flavor-dependent gauged lepton number $U(1)_\ell$ model for the hierarchical charged lepton masses and the observed $(g-2)_{e,\mu}$. Only tau participates in the tree-level Standard Model ( SM ) Yukawa interaction. At…
The bipair neutrino mixing describes the observed solar and atmospheric mixings; however, it predicts vanishing reactor mixing angle, which is inconsistent with the observed data. We explore the ways of minimally modifying the bipair…
We examine the charged boson and right-handed neutrino contribution to the muon g-2 anomaly in the twin Higgs models with the joint constraints of the Higgs global fit data, the precision electroweak data, the leptonic flavor changing decay…
We study a model with $U(1)$ gauged lepton number symmetry in which the active neutrino masses are generated at two-loop level through the spontaneous breaking of the lepton number symmetry. To cancel gauge anomalies some exotic leptons are…
We present here arguments in favor of the existence of the lightest lepton and its neutrino. This new family with a fourth lepton flavor uncovered so far unobserved universal properties of matter. The unity of the laws of their nature…
With regard to the leptonic magnetic dipole moment anomaly as well as the $W$-boson mass excess, we study the DFSZ axion model. Considering theoretical and experimental constraints, we show that the muon and electron $g-2$ anomalies can be…
The constraints on the mixing angles of the standard fermions with new heavy particles that can appear in many extensions of the electroweak theory are reviewed. Some emphasis is put in distinguishing the effects of a mixing with new states…
We discuss a model with a dark sector, in which smallness of mass for charged leptons and neutrinos can naturally be explained by one-loop effects mediated by particles in the dark sector. These new particles, including dark matter…
This paper reports the tenth-order QED contribution to lepton g-2 from diagrams of three gauge-invariant sets VI(d), VI(g), and VI(h), which are obtained by including various fourth-order radiative corrections to the sixth-order g-2…
We study the $K_L$ and $K_S$ decays into four leptons ($e\bar{e}e\bar{e}, \, \mu\bar{\mu}\mu\bar{\mu},\, e\bar{e}\mu\bar{\mu}$) where we use a form factor motivated by vector meson dominance, and show the dependence of the branching ratios…
The $\alpha^4$ contribution to the lepton $g-2$ from a gauge-invariant set of 18 Feynman diagrams containing a light-by-light scattering subdiagram internally has been reevaluated by a method independent of the previous approach. Comparison…
The very precise measurement of the anomalous magnetic moment of the muon, recently released by the Muon g-2 experiment at Fermilab, can serve to set stringent constraints on new particles. If the observed 4$\sigma$ discrepancy from the…
We discuss the extension of the matrix element method (MEM) to Next-to-Leading Order (NLO) in perturbation theory. In particular we focus on the production of a Standard Model Higgs boson which decays into four leptons.
We revisit the current experimental bounds on fourth-generation Majorana neutrino masses, including the effects of right handed neutrinos. Current bounds from LEPII are significantly altered by a global analysis. We show that the current…
The small neutrino mass observed in neutrino oscillations is nicely explained by the seesaw mechanism. Rich phenomenology is generally expected if the heavy neutrinos are not much heavier than the electroweak scale. A model with this…
We point out the importance of two-body final states of weak isosinglet neutral heavy leptons predicted in several models of new physics beyond the standard model. We concentrate on muon-type neutral heavy leptons $L_\mu^0$ with mass $M<2$…
In the work presented here, we have studied the impact of right handed neutrinos, which are introduced to account for the evidence of neutrino masses, on charged lepton flavour violating observables. In particular, we have focused on the…
We consider the effects of adding a fourth generation to a model with two compactified extra dimensions -- one warped and the other flat. The extra dimensions lead to towers of Kaluza-Klein (KK) Z bosons. Interestingly, the higher KK-Z…
The new measurement of the muon's anomalous magnetic moment released by the Muon g-2 experiment at Fermilab sets strong constraints on the properties of many new particles. Using an effective field theory approach to the interactions of…
We make a fresh evaluation of contributions to (g-2) of the muon in the framework of a preonic model with coloured vectorlike leptons and heavy coloured Z bosons and discuss their implications in the light of the recent Brookhaven…