Latest documents http://publikationen.ub.uni-frankfurt.de/index/index/ Tue, 07 Nov 2006 10:52:41 +0200 Tue, 07 Nov 2006 10:52:41 +0200 http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/2414 We discuss the multiplicity distribution of electron-positron pairs created in the strong electromagnetic fields of ultrarelativistic heavy-ion transits. Based on nonperturbative expressions for the N-pair creation amplitudes, the Poisson distribution is derived by neglecting interference terms. The source of unitarity violation is identified in the vacuum-to-vacuum amplitude, and a perturbative expression for the mean number of pairs is given. Christoph Best; Walter Greiner; Gerhard Soff article http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/2414 Tue, 11 Jul 2006 10:52:41 +0200 http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/2436 We evaluate the Delbrück scattering amplitude to all orders of the interaction with the external field of a nucleus employing nonperturbative electron Green's functions. The results are given analytically in form of a multipole expansion. Alexander Scherdin; Andreas Schäfer; Walter Greiner; Gerhard Soff article http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/2436 Fri, 07 Jul 2006 12:04:09 +0200