Coulomb corrections to e^{+}e^{} production in ultrarelativistic 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 ultrarelativistic energies. A controversial issue is the possible cancellation of Coulomb corrections to the Born term in the pair production crosssection. 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 crosssection of single pair production, while the other method gives the inclusive crosssection. We have also performed a thorough study of the electron propagator in the nonstatic 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.
 Publication:

Nuclear Physics A
 Pub Date:
 December 2001
 DOI:
 10.1016/S03759474(01)011095
 arXiv:
 arXiv:nuclth/0101024
 Bibcode:
 2001NuPhA.695..395B
 Keywords:

 Nuclear Theory;
 High Energy Physics  Phenomenology
 EPrint:
 31 pages LaTeX document, 10 postscript figures (expanded 3rd section, version to be published in Nucl. Phys. A)