Published August 31, 2009 | Version v1
Journal article

Photoproduction of J/psi and of high mass e(+)e(-) in ultra-peripheral Au plus Au collisions at root s(NN)=200 GeV

Description

We present the first measurement of photoproduction of J/Ψ and of two-photon production of high-mass e+e- pairs in electromagnetic (or ultra-peripheral) nucleus-nucleus interactions, using Au + Au data at √sNN. The events are tagged with forward neutrons emitted following Coulomb excitation of one or both Au* nuclei. The event sample consists of 28 events with me+e- > 2 GeV/c2 with zero like-sign background. The measured cross sections at midrapidity of dσ/dy (J/Ψ + Xn, y = 0) = 76 ± 33(stat) ± 11(syst) μb and d2σ/dm dy (e+e- + Xn, y = 0) = 86 ± 23(stat) ± 16(syst) μb/(GeV/c2) for me+e- (elementof) [2.0,2.8] GeV/c2 have been compared and found to be consistent with models for photoproduction of J/Ψ and QED based calculations of two-photon production of e+e- pairs.

Additional details

Publishing Information

Journal Title
Physics Letters. Section B
Journal Volume
679
Journal Issue
4
Journal Page Range
p. 321-329
ISSN
0370-2693
CODEN
PYLBAJ

Optional Information

Contract/Grant/Project number
KB0201021; AC02-98CH10886
Notes
doi 10.1016/j.physletb.2009.07.061
Collaborations
PHENIX Collaboration
Funding organization
USDOE SC Office of Science (United States)
Secondary number(s)
BNL--90648-2009-JA