TY  - JOUR
A1  - Adams, J.
A1  - Berger, Jens
A1  - Dietel, Thomas
A1  - Kollegger, Thorsten
A1  - Lange, Jens Sören
A1  - Stock, Reinhard
A1  - al., et
A1  - Collaboration, STAR
T1  - Production of e+ e- pairs accompanied by nuclear dissociation in ultraperipheral heavy-ion collisions
N2  - We present data on e+ e- pair production accompanied by nuclear breakup in ultraperipheral gold-gold collisions at a center of mass energy of 200 GeV per nucleon pair. The nuclear breakup requirement selects events at small impact parameters, where higher-order diagrams for pair production should be enhanced. We compare the data with two calculations: one based on the equivalent photon approximation, and the other using lowest-order quantum electrodynamics (QED). The data distributions agree with both calculations, except that the pair transverse momentum spectrum disagrees with the equivalent photon approach. We set limits on higher-order contributions to the cross section.
Y1  - 2004
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/3551
UR  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hebis:30-19031
ER  -