Production of electron-positron pairs on nuclei in the field of a bichromatic plane electromagnetic wave

The exact solution of the Dirac equation for an electron in the field of a bichromatic plane electromagnetic wave — with components that are monochromatic waves propagating in one direction — is used to calculate the probability of e⁺e^– pair production on a nucleus in the field of such a wave. This influence of the nucleus is treated perturbatively as an external Coulomb field. The cases of small and large values of the intensity parameters of the wave components are considered and the passage to the limit of a crossed field is discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 33–40, September, 1978.We are very grateful to V. R. Khalilov for a fruitful discussion of the results.     

Photoproduction of electron-positron pairs in the field of a nucleus and the field of a plane electromagnetic wave

The equivalent photon approximation is used to calculate the nuclear pair production cross section in the field of an electromagnetic wave of arbitrary intensity. The cases of low and high wave intensities are considered, as is the limiting approach to a constant field.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 15–20, May, 1977.     

Effect of electric field on photoproduction of electron-positron pairs

The cross section of electron-positron pair production by two circularly polarized photons in a static uniform electric field is calculated. The dependence of the cross section on the photon energy is determined. It is shown that the corrections to the cross section of the process involving photons of various polarizations are suppressed as compared to the situation with crossed fields.     

Resonance mechanism of the production of electron-positron pairs in a strong magnetic field

The Compton-like process γe ^± → e ^± e ⁺ e ^? involving the production of an electron-positron pair in the interaction of an ultrarelativistic electron with a soft x-ray photon in the vicinity of the polar cap of a magnetar is considered. It is shown that the amplitude for this reaction has a resonance character. A simple analytic expression is obtained for the electron-absorption coefficient. Possible astrophysical implications of the resonance process γe ^± → e ^± e ⁺ e ^? are discussed.     

Resonance bremsstrahlung of an electron by a nucleus in the field of a plane electromagnetic wave

The resonance behavior of the brems Strahlung of an electron by a nucleus in the field of a plane electromagnetic wave is investigated. The differential cross section of the process in the resonance region is calculated.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 12–17, March, 1980.The authors express their gratitude to A. A. Sokolov for his attention to this research.     

Interference effect in the photoproduction of electron-positron pairs on a nucleus in the field of two light waves

In the general relativistic case, the nonresonance photoproduction of electron-positron pairs on a nucleus in the field of two circularly polarized light waves propagating in one direction is theoretically investigated. It is shown that there are two essentially different kinematical regions: the noninterference region, where the Bunkin-Fedorov quantum parameters play the role of multiphoton parameters, and the interference region, where interference effects are important and where quantum interference parameters are treated as multiphoton parameters. The interference effect is found in the photoproduction of an electron-positron pair on a nucleus in the field of two light waves. This effect occurs in the interference region and is due to the production of an electron-positron pair in the plane spanned by the light wave vector and the incident-photon momentum and to stimulated correlated emission and absorption of photons of the two waves. The cross sections for pair photoproduction on a nucleus in the above kinematical regions are determined for moderately strong fields. It is shown that, in the interference region, the partial cross sections for the case where there is a correlated emission (absorption) of the same number of photons of the two waves can significantly exceed the corresponding cross sections in any other geometry.     

Electron in the field of a plane quantized monochromatic electromagnetic wave

An exact solution of the Dirac equation is found for an electron moving in the field of a plane quantized monochromatic electromagnetic wave of arbitrary polarization.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 55–58, August, 1973.     

Resonant electron-positron pair photoproduction on a nucleus in a pulsed light field

The resonant photoproduction of an electron-positron pair on a nucleus in the field of a pulsed light wave is studied theoretically. The approximation where the electromagnetic pulse duration is much longer than the characteristic time of wave oscillations is considered. The interaction of the electron and positron with the Coulomb potential of the nucleus is considered in the Born approximation. An analytical expression for the resonant differential cross section is derived for the range of moderately strong external fields. This cross section contains a resonant peak whose height and width are determined by the external pulsed wave characteristics. The resonant cross section for pair photoproduction on a nucleus in a pulsed laser field can exceed the corresponding cross section for pair photoproduction on a nucleus in the absence of an external field by an order of magnitude.     

Electron-positron pair formation in the field of a bichromatic plane electromagnetic wave

On the basis of the accurate solution of the Dirac equation for an electron in the field of a bichromatic plane wave consisting of two monochromatic waves propagating in the same direction, the probability of formation of an e⁺e^– pair by a quantum in the wave field is calculated. The cases of small and large intensities of the wave components are considered, together with the transition in the limit to a constant field.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 46–53, February, 1977.The authors thank A. A. Sokolov for his constant interest in the work and discussion of the results.     

Scalar particle with polarizability in the field of a plane electromagnetic wave and in an electric field

Exact solutions are obtained for the wave equations for a scalar particle that possesses polarizability in the field of a plane electromagnetic wave of arbitrary polarization and in a constant electric field.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 40–43, February, 1991.     

Production of e lectron-positron pairs on collision of a single photon with a plane electromagnetic wave

The production of electron-positron and boson pairs on collision of a single photon with an intense circularly polarized plane wave is considered. The accompanying polarization and spin effects are investigated.Translated from Izvestiya VUZ. Fizika, Vol. 11, No. 8, pp. 71–75, August, 1968.     

Electron in crossed constant electromagnetic fields and a plane wave field

The Dirac equation for an electron interacting with constant homogeneous orthogonal magnetic and electric fields (E = H) and with the field of a plane wave being propagated in a direction perpendicular sto E and H is solved exactly. The plane wave field is hence considered either classically or in a quantized manner, or as the field of a wave consisting of classical and quantized parts.