Related papers: Less suppressed mu-e-gamma and tau-mu-gamma loop a…
Two-loop corrections for the form factor in a massive Abelian theory are evaluated, which result from the insertion of massless fermion or scalar loops into the massive gauge boson propagator. The result is valid for arbitrary energies and…
There are several advantages of introducing adjoint superfields at intermediate energies around $M=10^{13}$ GeV. Such as (i) gauge couplings still unify (ii) neutrino masses and mixings are produced (iii) primordial lepton asymmetry can be…
Due to large QED anomalous dimensions of the electric and magnetic dipole operators, the rate of the rare muon decay mu --> e+gamma is suppressed by the factor [ 1- 8 alpha/pi ln(Lambda/m_mu) ], independent of the physics responsible for…
We introduce a continuous one-dimensional non-Hermitian matrix gauge potential and study its effect on dynamics of a two-component field. The model is emulated by a system of evanescently coupled nonlinear waveguides with distributed gain…
We recall how a new light gauge boson emerged in Supersymmetric extensions of the Standard Model with an extra singlet superfield, and how it could behave very much as a light pseudoscalar, with the corresponding symmetry broken at a scale…
We study the possibility of discovering resonances in $\mu^+e^- \to \mu^- e^+$ and $e^-e^- \to \mu^- \mu^-$ collisions. We begin with the closely related problem of muonium--antimuonium transitions, where the experimental limit has just…
Within the context of the extended bi-spinor gauge theory we describe a new off-shell realization of scalar supersymmetry (s-susy) of massless interacting fields with U(1), U(1) x SU(N) and U(1) x SU(N_1) x SU(N_2) gauge groups. S-susy acts…
We study the theory of a scalar in the fundamental representation of the internal supergroup $SU(N|M)$. Remarkably, for $M=N+1$ its tree-level mass does not receive quantum corrections at one loop from either self-coupling or interactions…
We perform a Bethe-Salpeter equation (BSE) evaluation of composite scalar boson masses in order to verify how these masses can be smaller than the composition scale. The calculation is developed with a constituent self-energy dependent on…
We present a detailed analysis of the factorization and all-order resummation of the double-logarithmic radiative corrections which determine the asymptotic behavior of the gauge theory amplitudes suppressed by the leading power of the…
We compare two most relevant loop induced muon number violating processes, \mu --> e \gamma and \mu-e conversion in nuclei, in constraining new physics. Because of much richer structure of the latter process it may be enhanced with respect…
As an illustration of general principles, the $W$-boson loop contribution to the amplitude for the decay $H\to \gamma \gamma$ is calculated within a specific model for the effective lagrangian describing the anomalous gauge boson couplings.…
Precision electroweak data suggests the existence of a light Standard Model Higgs boson. Its width is very narrow by an accident of the fermion mass hierarchies, and so slight perturbations to the theory induce dramatic changes in the…
$Z \to \gamma \gamma$ decay amplitude is considered and proven to be zero due to properties of polarization vectors and Bose statistics. Triangular diagrams for a pseudoscalar $\to \gamma \gamma$ and $Z \to \gamma \gamma$ processes with…
The strongly coupled lattice gauge models show an interesting mechanism of dynamical mass generation. If a suitable continuum limit can be found, one may think of it as an alternative to the Higgs mechanism. We present data on the spectrum,…
Very recently, we proposed an explanation of the discrepancy between the measured anomalous magnetic moment of the muon and the Standard Model (SM) prediction in which the dominant contribution to $(g-2)_\mu$ originates in Kaluza-Klein (KK)…
We examine the sensitivity of the process e+e- -> nu nubar gamma to extra gauge bosons, Z' and W', which arise in various extensions of the standard model. The process is found to be sensitive to W' masses up to several TeV, depending on…
An analysis is given of the decay $\mu \to e+ \gamma$ in an MSSM extension with a vectorlike generation. Here mixing with the mirrors allows the possibility of this decay. The analysis is done at the one loop level with the exchange of…
In the L_{\mu} - L_{\tau} model the 3.6$\sigma$ discrepancy between the predicted and measured values of the anomalous magnetic moment of positive muons can be explained by the existence of a new dark boson Z' with a mass in the sub-GeV…
While the muon $g-2$ anomaly can be successfully explained by some new physics models, most of them are severely constrained by the $\mu \to e \gamma$ bound. This tension is more transparent from the effective field theory perspective, in…