Related papers: Leptons and Photons
The charge $F_1(0)$ and the magnetic $F_2(0)$ form factors of heavy charged leptons have been shown in the framework of the perturbation theory to have imaginary part. The imaginary parts of the form factors for muon and tau lepton have…
The rest masses of the electron, the muon and of the stable mesons and baryons can be explained, within 1% accuracy, with the standing wave model, which uses only photons, neutrinos, charge and the weak nuclear force. We do not need…
Based on the experimental data and estimations of the charged leptons and quarks masses, a close power law with exponent 3/4 has been found, connecting charged leptons masses and up quarks masses. A similar mass relation has been suggested…
If new sequential leptons $E^\pm$ and $N^0$ exist, the LEP bound implies $m_E$, $m_N > M_Z/2$. The heaviness of the neutral lepton breaks away from the pattern of the first three generations. The minimal model is to have 4 left-handed…
Each of neutrinos has a non - zero mass and regardless of whether it is a Dirac or a Majorana mass, can possess both anapole and electric dipole moments. Between their form factors appears a connection, for example, at the longitudinal…
We search for lepton-flavor-violating tau decays into three leptons (electron or muon) using 535 fb^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. No evidence for these decays is observed and we…
In order to estimate the possibility to observe exotic physics in a neutrino telescope, it is essential to first understand the flux of atmospheric neutrinos, muons and dimuons. We study the production of these leptons by high-energy cosmic…
We propose a phenomenological form of the charged lepton mass matrix, which extends the idea of ``lopsided'' mass matrix in the literature. The features of the form are that both the 2-3 and 1-3 elements of the charged lepton mass matrix…
A charged lepton mass formula $(m_e +m_\mu + m_\tau)/(\sqrt{m_e}+\sqrt{m_\mu} + \sqrt{m_\tau})^2 =2/3$ is well-known. Since we can, in general, have two relations for three quantities, we may also expect another relation for the charged…
It is proposed that dark matter is the origin of neutrino mass, thereby linking inexorably two undisputed (and seemingly unrelated) pieces of evidence for physics beyond the Standard Model. Leptogenesis at the TeV scale may also be…
Minimal extensions of the Standard Model that are motivated by grand unified theories or superstring models with an E_6 symmetry can naturally predict heavy neutrinos of Dirac or Majorana nature. Such heavy neutral leptons violate the de-…
If massless leptonic photons associated to electron, muon or tau leptonic number exist they would have been emitted from supernova 1987a via the annihilation process $\nu\bar{\nu}\to\gamma_{l}\gamma_{l}$. By requiring that this process does…
We give an example of a purely bosonic model -- a rotor model on the 3D cubic lattice -- whose low energy excitations behave like massless U(1) gauge bosons and massless Dirac fermions. This model can be viewed as a ``quantum ether'': a…
Assuming that the leptons and quarks other than top are massless at tree level, we show that their masses may be induced by loops involving the top quark. As a result, the generic features of the fermion mass spectrum arise from…
In the context of the local gauge group $SU(3)_c\otimes SU(3)_L\otimes U(1)_X$, we look for possible four family models, where all the particles carry ordinary electric charges. Thirteen different anomaly-free fermion structures emerge, out…
We propose a way to reconcile the Standard Model of leptons with a purely vectorial theory. The observed neutrino is predicted to be massless. The unobservability of its partner and the $V-A$ structure of the weak currents are given the…
Several hundred million tau decays have been studied with the BaBar detector at the PEP-II e+e- collider at the SLAC National Accelerator Laboratory. Recent results on Charged Current Lepton Universality and two independent measurements of…
Neutrinoless tau-lepton decays into either three leptons (tau- -> l1- l2 l3) or one lepton and one K0S meson(tau- -> l- K0S) where lepton l means either an electron or muon, have been searched for using 48.6 fb^{-1} of data collected with…
Some extensions of the standard model predict the existence of particles having two units of leptonic charge, known as bileptons. One of such models is based on the $SU(3)_c\times SU(3)_L\times U(1)_X$ symmetry group (3-3-1 model, for…
We consider the possibility of studying new physics that singles out the tau-lepton at the LHC. We concentrate on the tau-lepton charge asymmetry in tau+tau- pair production as a tool to probe this physics beyond the Standard Model. We…