Related papers: $a \to e^+ e^-$ decay in a model with induced coup…
An interaction of a pseudoscalar particle with two photons induced by an external electromagnetic field is used to study the photon decay $\gamma \to \gamma a$ where a is a pseudoscalar particle associated with the Peccei-Quinn U(1)…
It is shown that the processes of electron(positron) scattering and $e^+e^-$ pair production in the Coulomb fields of two relativistic ions, can be expressed through the amplitudes of lepton scattering off the ion Coulomb field via Watson…
The axion decay $a \to e^+ e^-$ is investigated in the presence of a plasma and an external magnetic field. The results demonstrate a strong catalyzing influence of medium. The axion lifetime in the magnetic field of order $10^{15}$ G and…
Lepton flavor violated processes are strongly suppressed in the Standard Model, but can be sizable in some extended models. The current experimental bounds on decay modes $\ell'^{\pm} \to a \ell^{\pm}$ are much weaker than the other…
We point out that the cross-section for the process $e^+ e^- \to e^+ e^- \tau^+ \tau^-$ at LEP is large enough to allow for a study of the anomalous electromagnetic couplings of the $\tau$ lepton. We show that the present bounds on the…
We investigate the consequences of introducing a set of exotic doublet leptons which couple to the standard model leptons in a minimal way. Through these additional gauge invariant and renormalizable coupling terms, new sources of…
We evaluate several basic electrodynamic processes as modified by the presence of a very strong magnetic field, exceeding $B_{\rm Q} \equiv m^2/e = 4.4\times 10^{13}$ G. These results are needed to build models of dissipative phenomena…
The strongest electromagnetic fields in nature are created in high energy nuclear collisions and expected to change the dynamic scattering processes in the early stage. The magnetic field effect on the Drell-Yan process is investigated in…
The polarization operator of an axion in a degenerate gas of electrons occupying the ground-state Landau level in a superstrong magnetic field $H\gg H_0=m_e^2c^3/e\hbar =4.41\cdot 10^{13}$ G is investigated in a model with a tree-level…
Primordial magnetic fields present between the eras of neutrino decoupling and of positron-electron annihilation can lead to the emission of neutrino-anti neutrino pairs or axions by electrons in excited Landau levels, thereby changing the…
The process of electron-positron pair production by two photons in a strong magnetic field has been studied. The process kinematics is considered, and the probability amplitude for arbitrary polarizations of particles is found. The…
Magnetic fields mix axions with photons, allowing for the cyclotron process e -> e + a by virtue of an intermediate plasmon even if axions do not couple to electrons at tree level. The axion and longitudinal-plasmon dispersion relations…
The axion is a hypothetical particle associated with a possible solution to the strong CP problem and is a leading candidate for dark matter. In this paper we investigate the emission of axions by accelerated electrons. We find the emission…
We calculate the effect of magnetic fields on the magnetic dipole moment of leptons up to the quadratic order in the magnetic field, including the QCD contributions. Since the leading contribution, which is linear in the magnetic field,…
Spin and polarization effects and correlations between them in the processes of pair production by a photon and synchrotron radiation in a magnetic field are considered. Expressions for the probabilities of the processes with arbitrary…
We investigate the spin correlations between electron-positron pairs created from a photon when it scatters in a high-intensity laser pulse via the nonlinear Breit-Wheeler process. We find that the spin states of the generated…
We study single kaon production off the nucleon induced by electrons (positrons) i.e. $e^-(e^+) + N \rightarrow \nu_e (\bar \nu_e) + \bar K (K) + N^\prime$ at low energies. The possibility of observing these processes with the high…
Electron-positron pairs can be produced via the Schwinger mechanism in the presence of strong electric fields. In particular, the fields involved in $\alpha$ decay and nuclear fission are strong enough to produce them. The energy of the…
In this work we study the axion/axion-like particle production from the lepton-nucleon scattering in the low-energy region, i.e., the $\ell N\to \ell N a$ processes, $\ell$ being the electron or muon and $N$ the proton or neutron. We…
We investigate the effects induced by excited leptons, at the one-loop level, in the anomalous magnetic and weak-magnetic form factors of the leptons. Using a general effective Lagrangian approach to describe the couplings of the excited…