Production of $e^+e^-$ Pairs Accompanied by Nuclear Dissociation in Ultra-Peripheral Heavy Ion Collision

J. Adams

doi:10.1103/PhysRevC.70.031902

paper

Production of $e^{+} e^{-}$ Pairs Accompanied by Nuclear Dissociation in Ultra-Peripheral Heavy Ion Collision

arXiv:nucl-ex/0404012 · doi:10.1103/PhysRevC.70.031902

Abstract

We present the first data on $e^{+} e^{-}$ pair production accompanied by nuclear breakup in ultra-peripheral 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 corrections to the pair production cross section should be enhanced. We compare the pair kinematic distributions with two calculations: one based on the equivalent photon approximation, and the other using lowest-order quantum electrodynamics (QED); the latter includes the photon virtuality. The cross section, pair mass, rapidity and angular distributions are in good agreement with both calculations. The pair transverse momentum, $p_{T}$ , spectrum agrees with the QED calculation, but not with the equivalent photon approach. We set limits on higher-order contributions to the cross section. The $e^{+}$ and $e^{-}$ $p_{T}$ spectra are similar, with no evidence for interference effects due to higher-order diagrams.

6 pages with 3 figures Slightly modified version that will appear in Phys. Rev. C

Production of $e^{+} e^{-}$ Pairs Accompanied by Nuclear Dissociation in Ultra-Peripheral Heavy Ion Collision

Abstract

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Production of e+e− Pairs Accompanied by Nuclear Dissociation in Ultra-Peripheral Heavy Ion Collision

Abstract

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Cited by in corpus (71)

Production of $e^{+} e^{-}$ Pairs Accompanied by Nuclear Dissociation in Ultra-Peripheral Heavy Ion Collision