Related papers: Constraints on exotic lepton doublets with minimal…
The Standard Model predicts that the Higgs boson couples to the fermions in the mass eigenstates. We consider the effects of lepton flavor violating (LFV) $Z$ boson couplings in the case where the Higgs boson has flavor non-diagonal Yukawa…
The observation of charged lepton flavor violation is a clear sign of physics beyond the Standard Model (SM). In this work, we investigate the sensitivity of future lepton colliders to charged lepton flavor violation via on-shell production…
We examine the contributions of Majorana neutrinos to CP-violating WWZ and ZZZ self-couplings, using a model in which sterile neutrinos couple to the W and Z by mixing with a fourth-generation heavy lepton. We find that the induced form…
In recent years, evidence for lepton flavour universality violation beyond the Standard Model has been accumulated. In this context, a singly charged $SU(2)_L$ singlet scalar ($\phi^\pm$) is very interesting, as it can only have flavour…
We explore the effects of neutrino and electron mixing with exotic heavy leptons in the process e^+e^-\to W^+W^- within E_6 models. We examine the possibility of uniquely distinguishing and identifying such effects of heavy neutral lepton…
Axion-like particles (ALPs) with lepton-flavor violating couplings can be probed in exotic muon and tau decays. The sensitivity of different experiments depends strongly on the ALP mass and its couplings to leptons and photons. For ALPs…
New heavy leptons with standard model gauge couplings have well determined cross sections for pair production. A standard pattern of mass mixing implies that the most likely decays are $\tau^\prime\to W \nu'$ and $ \nu'\to W \tau$.…
While the Standard Model remains the prevailing description of natural phenomena, several observed phenomena continue to elude its explanation. To address these challenges, we investigate the Minimal Left-Right Symmetric Model, an immediate…
In the framework of general 3-3-1 models, we perform a global $\chi ^2$ fit at $95\%$ C.L. to the updated Z pole observables, including new data from atomic parity violation. We found scenarios where specific realizations of 3-3-1 models…
We investigate the experimental bounds on the Flavor-Violating (FV) couplings of the $Z$ boson to the charged leptons. In addition to the direct LHC searches for FV $Z$ decays to leptons, we investigate indirect bounds from…
We discuss the current status of lepton flavour universality observables in semileptonic charged and neutral current $B$ meson decays. We recapitulate the current experimental situation. Assuming the current tensions with the SM are of…
The leptons are viewed as composite objects, exhibiting anomalous magnetic moments and anomalous flavor-changing transition moments. The decay \mu \to e \gamma is expected to occur with a branching ratio of the same order as the present…
We discuss the case of simultaneous mixing of gauge bosons and mixing of fermions in a model independent way and for a variety of extra-fermion representations. In this context we analyze a class of lepton family violating processes, namely…
Heavy neutral leptons (HNLs) are an attractive minimal extension of the Standard Model, as is a singlet scalar $s$ mixing with the Higgs boson. If both are present, it is natural for HNLs to interact with $s$. For a light singlet,the decay…
Measuring the lepton anomalous magnetic moments $(g-2)$ and the rare decays of light pseudoscalar mesons into lepton pairs $P\to l^{+}l^{-} $, serve as important tests of the Standard Model. To reduce the theoretical uncertainty in the…
We investigate a gauge extension of the Standard Model in light of the observed hints of lepton universality violation in $b \to c \ell \nu$ and $b \to s \ell^+ \ell^-$ decays at BaBar, Belle and LHCb. The model consists of an extended…
We analyze possible lepton-flavor-violating decays of the $Z^0$ particle in a minimal extension of the Standard Model, in which one right-handed neutral field for each family has been introduced. Such rare leptonic decays are induced by…
Constraints on the whole spectrum of lepton flavor violating vertices are shown in the context of the standard two Higgs doublet model. The vertex involving the $e-\tau $ mixing is much more constrained than the others, and the decays…
We investigate lepton flavour violation in a class of minimal left-right symmetric models where the left-right symmetry is broken by triplet scalars. In this context we present a method to consistently calculate the triplet-Yukawa couplings…
The dipole moments of the leptons and quarks are matrices in flavor space, which can potentially reveal as much about the flavor structure of the theory as do the mass matrices. The off-diagonal elements of the dipole matrices lead to…