Journal article
Exclusive photoproduction of J/psi mesons at HERA
The European physical journal. C, Particles and fields, Vol.24(3), pp.345-360
07/01/2002
DOI: 10.1007/s10052-002-0953-7
Abstract
The exclusive photoproduction of J/psi mesons, gammap --> J/psip, has been studied in ep collisions with the ZEUS detector at HERA, in the kinematic range 20 < W < 290 GeV, where W is the photon-proton centre-of-mass energy. The J/psi mesons were reconstructed in the union and the electron decay channels using integrated luminosities of 38 pb(-1) and 55 pb(-1), respectively. The helicity structure of J/psi production shows that the hypothesis of s-channel helicity conservation is satisfied within two standard deviations. The total cross section and the differential cross-section dsigma/dt, where t is the squared four-momentum transfer at the proton vertex, are presented as a function of W, for \t\ < 1.8 GeV2. The t distribution exhibits an exponential shape with a slope parameter increasing logarithmically with W with a value b = 4.15 +/- 0.05(stat.)(-0.18)(+0.30)(syst.) GeV-2 at W = 90 GeV. The effective parameters of the Pomeron trajectory are alpha(P)(0) = 1.200 +/- 0.009(stat.)(-0.010)(+0.004) (syst.) and alpha(P)' = 0.115 +/- 0.018(stat.)(-0.015)(+0.008) (syst.) GeV-2.
Details
- Title: Subtitle
- Exclusive photoproduction of J/psi mesons at HERA
- Creators
- ZEUS CollaborationJ Repond (Contributor)
- Resource Type
- Journal article
- Publication Details
- The European physical journal. C, Particles and fields, Vol.24(3), pp.345-360
- DOI
- 10.1007/s10052-002-0953-7
- ISSN
- 1434-6044
- eISSN
- 1434-6052
- Publisher
- Springer Nature
- Number of pages
- 16
- Language
- English
- Date published
- 07/01/2002
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984627212602771
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