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Jörg Eichler - One of the best experts on this subject based on the ideXlab platform.

  • Electron–positron pair production in relativistic ion–atom collisions
    Physics Letters A, 2005
    Co-Authors: Jörg Eichler
    Abstract:

    Abstract The creation of electron–positron Pairs constitutes an example for the conversion of energy into mass. We here give a brief outline of the various processes and theoretical approaches in a simple fashion. We point out some recent results and difficulties that have yet to be overcome.

  • Electron-Positron pair production
    Relativistic Atomic Collisions, 1995
    Co-Authors: Jörg Eichler
    Abstract:

    This chapter elaborates the production of free electron–positron Pairs. The creation of free electron–positron Pairs is by far the dominant pair production process for extreme relativistic energies. The theoretically most clear-cut way to describe the production of free electron–positron Pairs is a formulation in terms of lowest-order quantum electrodynamics (QED) with external electromagnetic fields. In the center-of-mass system, the target and projectile nuclei merely serve as sources of time-dependent electromagnetic fields. Since energy-momentum conservation rules out pair creation by a single freely moving charge, the lowest-order QED process involves two moving nuclei, each of them interacting with the Electron-Positron field through the exchange of a single photon. The Sommerfeld–Maue wave functions for electrons and positrons are described. The limits of perturbative probabilities for single-pair production are presented. The electron–positron pair formation by the transient electromagnetic field of a moving charge for the case where the electron ends up in a bound state is also analyzed.

  • Production of free Electron-Positron Pairs in relativistic heavy-ion collisions.
    Physical review. A Atomic molecular and optical physics, 1993
    Co-Authors: D. C. Ionescu, Jörg Eichler
    Abstract:

    The production of free Electron-Positron Pairs in relativistic heavy-ion collisions is investigated within first-order time-dependent perturbation theory. An analytic expression for the differential pair-production cross section is obtained by employing Furry-Sommerfeld-Maue wave functions for the description of continuum states in the external field of the target nucleus. The angular distributions of electrons and positrons and cross sections are calculated and compared with previous results.

  • Angular distribution of Electron-Positron Pairs produced in relativistic heavy-ion collisions.
    Physical Review A, 1992
    Co-Authors: Frank Decker, Jörg Eichler
    Abstract:

    Angular distributions of free Electron-Positron Pairs produced in relativistic ion-atom collisions are calculated within a first-order Born approximation. The electron and positron continuum states in the field of the high-Z target nucleus are described by relativistic Sommerfeld-Maue wave functions. The cross-section dependence on the polar angles and on the lepton energies is calculated for several experimentally relevant cases. The azimuthal anisotropy for given polar angles is also presented.

Rainer Grobe - One of the best experts on this subject based on the ideXlab platform.

  • Creation of electron–positron Pairs in oscillating electric fields
    Journal of the Optical Society of America B, 2015
    Co-Authors: Rainer Grobe
    Abstract:

    By solving the time-dependent Dirac equation numerically, we calculate the rate of electron–positron Pairs that are created from the vacuum by an oscillating field. The data permit us to examine the validity of approximate, but analytical, expressions derived from the WKB-based description. If two characteristic parameters (E/c3 and ω/c2) are less than 1 or the parameter γ(=ωc/E) is small (tunneling region), this description predicts the true rate well, where E and ω are the amplitude and frequency of the external field. In the multi-photon region (where E/c3 is small and γ is large), perturbative methods become valid.

  • Electron-Positron pair creation induced by quantum-mechanical tunneling
    Physical Review A, 2011
    Co-Authors: M. Jiang, Z. M. Sheng, Jie Zhang, Rainer Grobe
    Abstract:

    We study the creation of Electron-Positron Pairs from the vacuum induced by two spatially displaced static electric fields. The strength and spatial width of each localized field is less than required for pair creation. If, however, the separation between the fields is less than the quantum-mechanical tunneling length associated with the corresponding quantum scattering system, the system produces a steady flux of Electron-Positron Pairs. We compute the time dependence of the pair-creation probability by solving the Dirac equation numerically for various external field sequences. For the special case of two very narrow fields we provide an analytical expression for the pair-creation rate in the long-time limit.

  • Creation of multiple Electron-Positron Pairs in arbitrary fields
    Physical Review A, 2009
    Co-Authors: T. Cheng, Rainer Grobe
    Abstract:

    We examine the spontaneous breakdown of the matter vacuum triggered by an external force of arbitrary strength and spatial and temporal variations. We derive a nonperturbative framework that permits the computation of the complete time evolution of various multiple Electron-Positron pair probabilities. These time-dependent probabilities can be computed from a generating function as well as from solutions to a set of ratelike equations with coupling constants determined by the single-particle solutions to the time-dependent Dirac equation. This approach might be of relevance to the planned experiments to observe for the first time the laser-induced breakdown process of the vacuum.

  • Classical-quantum correspondence in Electron-Positron pair creation
    Physical Review A, 2007
    Co-Authors: N. I. Chott, Rainer Grobe
    Abstract:

    We examine the creation of Electron-Positron Pairs in a very strong force field. Using numerical solutions to quantum field theory we calculate the spatial and momentum probability distributions for the created particles. A comparison with classical mechanical phase space calculations suggests that despite the fully relativistic and quantum mechanical nature of the matter creation process, most aspects can be reproduced accurately in terms of classical mechanics.

Gerhard Baur - One of the best experts on this subject based on the ideXlab platform.

  • Higher-order processes in the electromagnetic production of Electron-Positron Pairs in relativistic heavy-ion collisions.
    Physical Review A, 1995
    Co-Authors: Kai Hencken, Dirk Trautmann, Gerhard Baur
    Abstract:

    We study higher-order effects in the electromagnetic production of Electron-Positron Pairs in relativistic heavy-ion collisions. Treating the field of the heavy ions as an external field and neglecting the interaction among electrons and positrons, we show that the [ital N]-pair creation amplitude is the antisymmetrized product of [ital N] one-pair creation amplitudes and the vacuum amplitude. Neglecting contributions coming from exchange terms, we show that the total probability for [ital N] Pairs is approximately a Poisson distribution. We investigate further the structure of the reduced one-pair amplitude, concentrating especially on multiple-particle corrections. We calculate the first of these corrections in second-order Magnus theory based on our previous result [Phys. Rev. A 49, 1584 (1994)] in the second-order Born approximation for impact parameter [ital b] zero. Explicit calculations show that the total probability is increased up to 10% by this correction for realistic collider parameters. The calculations can also be used to confirm the use of the Poisson distribution for the total probability.

M. Y. Şengül - One of the best experts on this subject based on the ideXlab platform.

Bai-song Xie - One of the best experts on this subject based on the ideXlab platform.

  • Electron-Positron pair production in frequency modulated laser fields
    Physical Review D, 2020
    Co-Authors: C. Gong, Bai-song Xie
    Abstract:

    The momentum spectrum and the number density of created Electron-Positron Pairs in a frequency modulated laser field are investigated using quantum kinetic equation. It is found that the momentum spectrum presents obvious interference pattern. This is an imprint of the frequency modulated field on the momentum spectrum, because the momentum peaks correspond to the pair production process by absorbing different frequency component photons. Moreover, the interference effect can also be understood qualitatively by analyzing turning point structures. The study of the pair number density shows that the number density is very sensitive to modulation parameters and can be enhanced by over two orders of magnitude for certain modulation parameters, which may provide a new way to increase the number of created Electron-Positron Pairs in future experiments.

  • Electron-Positron pair production in an oscillating Sauter potential
    Physical Review A, 2019
    Co-Authors: Li Wang, Bai-song Xie
    Abstract:

    Electron-Positron pair production in an oscillating Sauter potential is investigated in the framework of the computational quantum field theory. It is found that for a Sauter potential well with oscillating width and depth simultaneously, the phase difference between them has a great impact on the number of created Electron-Positron Pairs. Optimal values of the phase difference corresponding to different oscillation frequencies are obtained. The optimal phase difference has a strong nonlinear dependence on oscillating frequency. When the potential well changes slowly, our results can be explained by the instantaneous bound states. For the higher frequency case, however, multiphoton effect is enhanced and the Pauli blocking effect has a strong inhibitory effect on pair creations. These results can provide a theoretical reference for the experimental creation of the Electron-Positron Pairs.