Related papers: Constraints on lepton number violating short-range…
We study the phenomenology of d=7 1-loop neutrino mass models. All models in this particular class require the existence of several new $SU(2)_L$ multiplets, both scalar and fermionic, and thus predict a rich phenomenology at the LHC. The…
We extend the effective theory of Minimal Lepton Flavor Violation (MLFV) by including four-lepton operators. We compute the rates for mu -> 3 e and tau -> 3 ell decays and point out several new ways to test the hypothesis of MLFV. We also…
We study two- and three-body lepton flavor violating (LFV) decays involving leptons and neutral vector bosons $V=\rho^0, \omega, \phi, J/\psi, \Upsilon, Z^0$, as well as pseudo-scalar $P=\pi^0, \eta, \eta', \eta_c$ and scalar $S=f_0(500),…
We propose an $SU(3)_C\times SU(2)_L\times U(1)_{Y}\times U(1)_{B-L}$ model, in which the neutrino masses and mixings can be generated via Type-I seesaw mechanism after $U(1)_{B-L}$ breaking. A light mediator emerges and enables…
Lepton number violation (LNV) can be induced by Majorana neutrinos in four-body decays of the neutral B meson and the top quark. We study the effects of Majorana neutrinos in these |\Delta L|=2 decays in an scenario where a single heavy…
New interactions with Lorentz scalar structure, arising from physics beyond the standard model of electroweak interactions, will induce effective pseudoscalar interactions after renormalization by weak interaction loop corrections. Such…
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…
Mixing between bosons that transform differently under the standard model gauge group, but identically under its unbroken subgroup, can induce interactions that violate the total lepton number. We discuss four-fermion operators that mediate…
In the context of the minimal supersymmetric seesaw model, we study the implications of the current neutrino data for thermal leptogenesis, $\beta\beta_{0\nu}$ decay, and leptonic flavour- and CP-violating low-energy observables. We express…
The constraints on baryogenesis models obtained from an observation of neutrinoless double beta decay are discussed. The lepton number violating processes, which can underlie neutrinoless double beta decay, would together with sphaleron…
We investigate the constraints on four-Fermi contact interactions from low-energy lepton-quark and lepton-lepton scattering experiments --- polarization asymmetries in electron (muon)-nucleon scattering experiments, cesium and thallium atom…
A general Lorentz-invariant parameterization for the short-range part of the 0vBB decay rate is derived. Combined with the long range part already published this general parameterization in terms of effective B-L violating couplings allows…
The parity solution to the strong CP problem necessarily extends the Standard Model to include the SU$(2)_{\rm R}$ gauge sector and imposes restrictions on the structure of the Yukawa interactions. In this framework, one can consider an…
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…
Within the Standard Model, the weak interaction of quarks and leptons is characterized by certain symmetry properties, such as maximal breaking of parity and favored helicity. These are related to the $V-A$ structure of the weak…
We present a new class of constraints to the lepton-family number and R-parity violating couplings from muonium conversion, $\mu^{-} + {_{22}^{48}} Ti \to e^{-} + {_{22}^{48}} Ti$, a class of tau decays, $\tau \to l +$ (light meson) with…
We consider lepton-flavor violation in strangeness changing ($|\Delta S|=1$) semileptonic $\tau$-lepton decays arising from new physics encoded in a standard model effective Lagrangian. Its invariance under the standard model gauge group…
The lepton number violating process can be induced by introducing a fourth generation heavy Majorana neutrino, which is coupled to the charged leptons of Standard Model. There have been many previous studies on the leptonic number violating…
After discussion of mechanisms of lepton number violation, we consider meson decays $K^+ \to\pi^ - \ell ^ + \ell '^ +$ and $D^ + \to K^ - \ell ^ + \ell '^ +$ ($\ell,\ell ' = e,\mu $) with $\Delta L= 2$ in the Standard Model extended by…
We derive the upper bounds on certain products of R-parity- and lepton-flavor-violating couplings from $B^\pm \to l^\pm \nu$ decays. These modes of B-meson decays can constrain the product combinations of the couplings with one or more…