Production of e+ e- pairs accompanied by nuclear dissociation in ultraperipheral heavy-ion collisions
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.
| Author: | J. Adams, Jens Berger, Thomas Dietel, Thorsten Kollegger, Jens Sören Lange, Reinhard Stock, et al., STAR Collaboration |
|---|---|
| URN: | urn:nbn:de:hebis:30-19031 |
| Document Type: | Article |
| Language: | English |
| Date of Publication (online): | 14.10.2005 |
| Year of first Publication: | 2004 |
| Publishing Institution: | Univ.-Bibliothek Frankfurt am Main |
| Source: | Phys. Rev. C 70, 031902 (2004), ©2004 The American Physical Society, http://link.aps.org/abstract/PRC/v70/e031902 |
| HeBIS PPN: | 191775223 |
| Institutes: | Physik |
| Dewey Decimal Classification: | 530 Physik |
| PACS-Classification: | 12.20.-m Quantum electrodynamics |
| 25.20.Lj Photoproduction reactions | |
| 25.75.Dw Particle and resonance production | |
| Sammlungen: | Universitätspublikationen |
| Licence (German): |  Veröffentlichungsvertrag für Publikationen ohne Print on Demand |
