Photoproduction of J/psi and of High Mass e+e- in Ultra-Peripheral Au+Au Collisions at s**(1/2) = 200 GeV
- University of Colorado, Boulder
- ORNL
- University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL)
- Oak Ridge National Laboratory (ORNL)
- University of Tennessee, Knoxville (UTK)
We present the first measurement of photoproduction of J/{psi} and of two-photon production of high-mass e{sup +}e{sup -} pairs in electromagnetic (or ultra-peripheral) nucleus-nucleus interactions, using Au + Au data at {radical}s{sub NN} = 200 GeV. 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 m{sub e{sup +}e{sup -}} > 2 GeV/c{sup 2} with zero like-sign background. The measured cross sections at midrapidity of d{sigma}/dy (J/{psi} + Xn,y = 0) = 76 {+-} 33(stat) {+-} 11(syst) {mu}b and d{sup 2}{sigma}/dm dy(e{sup +}e{sup -} + Xn, y = 0) = 86 {+-} 23(stat) {+-} 16(syst) {mu}b/(GeV/c{sup 2}) for m{sub e{sup +}e{sup -}} {element_of} [2.0,2.8] GeV/c{sup 2} have been compared and found to be consistent with models for photoproduction of J/{psi} and QED based calculations of two-photon production of e{sup +}e{sup -} pairs.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 988262
- Journal Information:
- Physics Letters B, Vol. 679, Issue 4
- Country of Publication:
- United States
- Language:
- English
Similar Records
Photoproduction of J/ψ and of high mass e+e− in ultra-peripheral Au +Au collisions at root sNN = 200 GeV
Photoproduction of J/ψ and of high mass e+e− in ultra-peripheral Au +Au collisions at root sNN = 200GeV