The optical theorem is applied to the process of electron-positron pair creation in the superposition of a nuclear Coulomb and a strong laser field. We derive representations for the total production rate as twofold integrals, both for circular laser polarization and for the general case of elliptic polarization. Our approach allows us to obtain, by analytical means, the asymptotic behavior of the pair creation rate for various limits of interest. In particular, we consider pair production by two-photon absorption and show that, close to the energetic threshold of this process, the rate obeys a power law in the laser frequency with different exponents for linear and circular laser polarization. With the help of the upcoming x-ray laser sources, our results could be tested experimentally.
A. I. Milstein et al., "Polarization-Operator Approach to Electron-Positron Pair Production in Combined Laser and Coulomb Fields," Physical Review A - Atomic, Molecular, and Optical Physics, vol. 73, no. 6, pp. 062106-1-062106-10, American Physical Society (APS), Jun 2006.
The definitive version is available at http://dx.doi.org/10.1103/PhysRevA.73.062106
Keywords and Phrases
Asymptotic Stability; Electromagnetic Fields; Electrons; Lasers; Natural Frequencies; Positrons; Asymptotic Behavior; Elliptic Polarization; Laser Frequency; Laser Polarization; Light Polarization
International Standard Serial Number (ISSN)
Article - Journal
© 2006 American Physical Society (APS), All rights reserved.