Structure of the Coulomb and unitarity corrections to the cross section ofe+e−pair production in ultrarelativistic nuclear collisions

Abstract

We analyze the structure of the Coulomb and unitarity corrections to the single e + e − pair production as well as the cross section σ n for the multiple pair production in collision of ultrarelativistic nuclei. In the external field approximation we consider the probability of one pair production at fixed impact parameter ρ between colliding nuclei. We obtain the analytical result for this probability at large ρ as compared to the electron Compton wavelength. The energy dependence of this probability as well as that of σ n differ essentially from widely cited but incorrect results. We estimate also the unitary corrections to the total cross section of the process.

Physics of Ultra-Peripheral Nuclear Collisions

“…Ref. [123] claims that this expression is wrong. They derived expressions for this probability using two different methods.…”

“…They derived expressions for this probability using two different methods. Reference [123] obtains σ n ∝ L n , whereas References [118] and [124] obtain σ n ∝ L 3n respectively.…”

“…A general sum of the contribution of diagrams like those in Figure 1(e,f) and unitarity corrections (involving the production of virtual e + e − pairs) was obtained in Reference [123]. To account for Coulomb distortions, one needs to add to eq.…”

Double lepton pair production with electron capture in relativistic heavy-ion collisions

“…[5,6]. In the present study, therefore, we will restrict ourselves to a short account of the basic formulas and ideas, which are needed to derive the σ ee and probability P(ρ) of the boundfree pair production.…”

“…However, while in the past most of the studies have dealt with single e + e − pairs, much of today interest is focused also on the multiple pair production. Such a process, in which few electrons and positrons are created in a single collision event, is of high order in the electromagnetic coupling α and is predicted to have a sufficiently large cross section [4,5]. Its analysis can help, therefore, to improve our understanding of the non-linear QED effects in quantum vacuum.…”