Coulomb corrections to e+e− production in ultra-relativistic nuclear collisions

✍ Scribed by A.J. Baltz; F. Gelis; L. McLerran; A. Peshier

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 300 KB
• Volume: 695
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/s0375-9474(01)01109-5

✦ Synopsis

The purpose of this paper is to explain the discrepancies existing in the literature relative to e + e -pair production in peripheral heavy ion collisions at ultra-relativistic energies. A controversial issue is the possible cancellation of Coulomb corrections to the Born term in the pair production cross-section. Such a cancellation has been observed in a recent approach based on finding retarded solutions of the Dirac equation, but does not seem to hold in a perturbative approach. We show in this paper that the two approaches are in fact calculating different observables: the perturbative approach gives the exclusive cross-section of single pair production, while the other method gives the inclusive cross-section.

We have also performed a thorough study of the electron propagator in the non-static background field of the two nuclei, the conclusion of which is that the retarded propagator is in the ultrarelativistic limit a much simpler object than the Feynman propagator, and can be calculated exactly.