Exclusive photoproduction of Upsilon mesons at HERA

                       ZEUS Collaboration
 
                           Abstract 

The exclusive photoproduction reaction gamma p -> Upsilon p has been 
studied with the ZEUS experiment in ep collisions at HERA using an 
integrated luminosity of 468 pb^-1. The measurement covers the kinematic 
range 60<W<220 GeV and Q^2<1 GeV^2, where W is the photon-proton 
centre-of-mass energy and Q^2 is the photon virtuality. These results, 
which represent the analysis of the full ZEUS data sample for this channel, 
are compared to predictions based on perturbative QCD.