# Diffractive photoproduction of $j/\psi$ mesons with large momentum transfer at HERA

Abstract : The diffractive photoproduction of J/psi mesons is measured with the H1 detector at the ep collider HERA using an integrated luminosity of 78 pb^-1. The differential cross section d sigma(gamma p -> J/psi Y) / d t is studied in the range 2 < |t| < 30 GeV^2, where t is the square of the four-momentum transferred at the proton vertex. The cross section is also presented as a function of the photon-proton centre-of-mass energy W in three t intervals, spanning the range 50 < W < 200 GeV. A fast rise of the cross section with W is observed for each t range and the slope for the effective linear Pomeron trajectory is measured to be alpha^\prime= -0.0135 \pm 0.0074 (stat.) \pm 0.0051 (syst.) GeV^-2. The measurements are compared with perturbative QCD models based on BFKL and DGLAP evolution. The data are found to be compatible with s-channel helicity conservation.
Document type :
Journal articles

Cited literature [14 references]

http://hal.in2p3.fr/in2p3-00014098
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Submitted on : Tuesday, November 4, 2003 - 9:33:08 AM
Last modification on : Wednesday, April 7, 2021 - 3:26:01 PM
Long-term archiving on: : Tuesday, March 30, 2010 - 6:02:21 PM

### Identifiers

• HAL Id : in2p3-00014098, version 1

### Citation

A. Aktas, V. Andreev, T. Anthonis, A. Astvatsatourov, A. Babaev, et al.. Diffractive photoproduction of $j/\psi$ mesons with large momentum transfer at HERA. Physics Letters B, Elsevier, 2003, 568, pp.205-218. ⟨in2p3-00014098⟩

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