Coulomb corrections to e+e- production in ultra-relativistic nuclear collisions
Abstract
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 ultra-relativistic limit a much simpler object than the Feynman propagator, and can be calculated exactly.
- Publication:
-
Nuclear Physics A
- Pub Date:
- December 2001
- DOI:
- 10.1016/S0375-9474(01)01109-5
- arXiv:
- arXiv:nucl-th/0101024
- Bibcode:
- 2001NuPhA.695..395B
- Keywords:
-
- Nuclear Theory;
- High Energy Physics - Phenomenology
- E-Print:
- 31 pages LaTeX document, 10 postscript figures (expanded 3rd section, version to be published in Nucl. Phys. A)