Published in:
Physical Review C 70,3 (2004) 031902;
Link to original published article:
http://dx.doi.org/10.1103/PhysRevC.70.031902
Abstract
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.
Keywords
time projection chamber;; gamma-gamma;; colliders;; photon
Date of this Version
January 2004