Energy dependence for pair production with electron capture inrelativistic heavy-ion collisions

Abstract

In `Charge transfer from the negative-energy continuum:alternative mechanism for pair production in relativisticatomic collisions', Eichler (1995 Phys. Rev. Lett. 75 3653) proposes an alternative mechanismfor capture by pair production, and from it derives ananalytic expression for the total cross section with asurprisingly strong energy dependence. We show that, infact, there is no alternative mechanism; rather the abovemechanism may be more transparently viewed as anionization-like transition in one centre with inclusionof continuum distortion by the second centre. We furthershow that to centre the initial and final states on thetarget and projectile leads to confusion in the momentumtransfer vectors, and hence, respectively that thealleged high-energy behaviour is erroneous.