Related papers: Electron-positron annihilation into two photons in…
Under quite generic assumptions the general expression is derived for the probability of circularly polarized photon emission from the longitudinally polarized electron and for the probability of pair creation of longitudinally polarized…
Recent and ongoing experimental work on the positronium spectrum motivates new efforts to calculate positronium energy levels at the level of three loop corrections. We have obtained results for one set of such corrections involving…
Process of muon (pion) pair production with small invariant mass in the electron-positron high-energy annihilation, accompanied by emission of hard photon at large angles, is considered. We find that the Dell-Yan picture for differential…
Electron-photon quantum entanglement in an electron microscope paves the way for a new quantum platform, enabling the integration of quantum functionalities into electron microscopy and opening opportunities for quantum imaging and quantum…
The strong corrections to the R-ratio of electron-positron annihilation into hadrons are studied at the higher-loop levels. Specifically, the essentials of continuation of the spacelike perturbative results into the timelike domain are…
The interaction of high energy electrons, positrons, and photons with intense laser pulses is studied in head-on collision geometry. It is shown that electrons and/or positrons undergo a cascade-type process involving multiple emissions of…
We consider the vacuum decay by electron-positron pair production in spatially homogeneous, time dependent electric fields by means of quantum kinetic equations. Our focus is on the impact of various pulse shapes as envelopes of oscillating…
We developed a method to analyze the polarization correlations of two baryons $B_{1}\bar{B}_{2}$ with various spin combinations in the annihilation process. We established spin density matrices for arbitrary spins in standard and Cartesian…
Quantum entanglement between gamma-ray photons emitted following electron-positron annihilation is expected to be maximal and may be characterized via non-classical polarization correlations. However, this is difficult to verify…
The term two--photon processes is used for the reactions in which some system of particles is produced in collision of two photons, either real or virtual. In the study of these processes our main goal was to suggest approach, allowing to…
Propylene oxide, a favorite target of experimental and theoretical studies of circular dichroism, was recently discovered in interstellar space, further amplifying the attention to its role in the current debate on protobiological…
The differential cross-section of the single-photon annihilation of channeled positron on the K-shell electron of one of the crystal atoms is calculated and angular distribution of emitted photons is investigated. It is shown that…
Studies based on imaging the annihilation of the electron (e$^{-}$) and its antiparticle positron (e$^{+}$) open up several interesting applications in nuclear medicine and fundamental research. The annihilation process involves both the…
The rate for complete two-photon annihilation of molecular positronium Ps$_{2}$ is reported. This decay channel involves a four-body collision among the fermions forming Ps$_{2}$, and two photons of 1.022 MeV, each, as the final state. The…
We predict breakdown of the electric dipole approximation at nonlinear Cooper minimum in direct two-photon $K-$shell atomic ionisation by circularly polarised light. According to predictions based on the electric dipole approximation, we…
We consider the one-photon annihilation mechanism in a electron - positron quasiparticle plasma (EPP) created from the vacuum in a strong subcritical laser field due to the dynamical Schwinger mechanism. On the basis of a kinetic theory…
The energy and momentum conservation laws prohibit positron-electron annihilation in vacuum producing the single photon only. It can produce two photons in vacuum, or the process is possible with a participation of the third body. The…
Radiative corrections to the annihilation of proton--antiproton into electron--positron are revisited, including virtual and real (soft and hard) photon emission. This issue is relevant for the time-like form factors measurements planned at…
Positron and electron cosmic rays provide a complementary way to study the galactic environment. The actual cosmic rays experiments, for instance PAMELA and HEAT, have presented very exciting results in this field. The observed positron…
The s-channel annihilation of proton and antiproton into a neutral pion and a real or virtual photon followed by lepton pair emission is studied. Such mechanism is expected to play a role at moderate values of the total energy $\sqrt{s}$,…