Related papers: Positronium decay in a circular polarized laser fi…
We demonstrated for the first time the production of highly polarized short-pulse positrons with a finite energy spread in accordance with a new scheme that consists of two-quantum processes, such as inverse Compton scatterings and…
The use of bichromatic counter-rotating laser field is known to generate high-order harmonics with non-zero ellipticity. By combining such laser field with a plasmonic-enhanced spatially inhomogeneous field, we propose a way to influence…
Results of Positron Annihilation Lifetime Spectroscopy (PALS) and microscopic studies on simple microorganisms: brewing yeasts are presented. Lifetime of ortho - positronium (o-Ps) were found to change from 2.4 to 2.9 ns (longer lived…
Factors limiting the operating lifetime of Compact Surface Plasma Sources (CSPS) are analyzed and possible treatments for lifetime enhancement are considered. Noiseless discharges with lower gas and cesium densities are produced in…
We construct an effective Lagrangian for interacting pions with non-relativistic energies. The coupling constants can be expressed in terms of the different scattering lengths and slopes. When used in the calculation of the pionium decay…
Radiative polarization of electrons and positrons through the Sokolov-Ternov effect is important for applications in high-energy physics. Radiative spin-polarization is a manifestation of quantum radiation reaction affecting the…
The features of electromagnetic processes are considered which connected with finite size of space region in which final particles (photon, electron-positron pair) are formed. The longitudinal dimension of the region is known as the…
Relativistic corrections to the positronium decay rate are calculated. They are close to $40(\alpha /\pi)^2$ and $46(\alpha /\pi)^2$ for singlet and triplet states respectively.
The dynamics of fast (e, 2e) collisions, induced by the impact of twisted electron beams, on atomic hydrogen, is analyzed in the presence of a laser field with circular and linear polarization. For the (e,2e) differential cross-section…
Low energy $p\bar p$ interaction is considered taking into account the polarization of both particles. The corresponding cross sections are calculated using the Paris nucleon-antinucleon optical potential. Then they are applied to the…
Aiming at the investigation of above-threshold ionization in super-strong laser fields with highly charged ions, we develop a Coulomb-corrected strong field approximation (SFA). The influence of the Coulomb potential of the atomic core on…
We study the ionization dynamics of oriented HeH$^+$ in strong linearly-polarized laser fields by numerically solving the time-dependent Schr\"{o}dinger equation. The calculated photoelectron momentum distributions for parallel orientation…
Considering the effective Euler-Heisenberg Lagrangian, i.e., non-linear photon-photon interactions, we study the circular polarization of electromagnetic radiation based on the time-evolution of Stokes parameters. To the leading order, we…
Currently, the experimental uncertainty for the determination of the ortho-positronium (o-Ps) decay rate is at 150 ppm precision; this is two orders of magnitude lower than the theoretical one, at 1 ppm level. Here we propose a new proof of…
We consider emission of a photon by an electron in the field of a strong laser wave. Polarization effects in this process are important for a number of physical problems. We discuss a probability of this process for circularly polarized…
We report a 4.9\,ppb measurement of the positronium $\text{1}^\text{3}\text{S}_\text{1} \to \text{2}^\text{3}\text{S}_\text{1}$ interval using continuous-wave two-photon laser spectroscopy. The transition is detected via photoionization by…
Positronium (Ps) scattering by noble-gas atoms (He, Ne, Ar, Kr, and Xe) is studied in the frozen-target approximation and with inclusion of the van der Waals interaction. Single-particle electron and positron states in the field of the…
Development of QED cascades in a standing electromagnetic wave for circular and linear polarizations is simulated numerically with a 3D PIC-MC code. It is demonstrated that for the same laser energy the number of particles produced in a…
Long-lived particles (LLPs) provide an interesting window into physics beyond the Standard Model, offering characteristic signatures at colliders and in cosmology. In this work, we investigate LLPs decays into dark matter. If the lifetime…
The discrepancy between the experimental decay rate of orthopositronium (o-Ps) and the QED theoretical prediction can be solved by invoking decays of o-Ps into exotic particles with branching ratios of the order of 10^{-3}. We show that…