Document Type
Article
Publication Date
1-1-1997
Abstract
The reaction γ p → J/ψ p has been studied in ep interactions using the ZEUS detector at HERA. The cross section for elastic J/ψ photoproduction has been measured as a function of the photon-proton centre of mass energy W in the range 40 < W < 140 GeV at a median photon virtuality Q2 of 5 × 10-5 GeV2. The photoproduction cross section, σγp→J/ψp, is observed to rise steeply with W. A fit to the data presented in this paper to determine the parameter δ in the form σγp→J/ψp α Wδ yields the value δ = 0.92±0.14±0.10. The differential cross section dσ/d|t| is presented over the range |t| < 1.0 GeV2 where t is the square of the four-momentum exchanged at the proton vertex. dσ/d|t| falls exponentially with a slope parameter of 4.6 ± 0.4-0.6+0.4 GeV-2. The measured decay angular distributions are consistent with s-channel helicity conservation. © Springer-Verlag 1997.
Journal Title
Zeitschrift fur Physik C-Particles and Fields
Volume
75
Issue
2
First Page
215
Last Page
228
DOI
https://doi.org/10.1007/s002880050464
First Department
Physics
Recommended Citation
Breitweg, J.; Derrick, M.; Krakauer, D.; Magill, S.; Mikunas, D.; Musgrave, B.; Repond, J.; Stanek, R.; Talaga, R. L.; Yoshida, R.; Zhang, H.; Mattingly, Margarita C. K.; Anselmo, F.; Antonioli, P.; Bari, G.; Basile, M.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Cara Romeo, G.; Castellini, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; De Pasquale, S.; Gialas, I.; Giusti, P.; Iacobucci, G.; and Laurenti, G., "Measurement of Elastic J/Ψ Photoproduction st HERA" (1997). Faculty Publications. 2705.
https://digitalcommons.andrews.edu/pubs/2705
Acknowledgements
Open access article retrieved April 5, 2021 from https://link.springer.com/article/10.1007/s002880050464