Description
Using the full HERA data set of 468 $pb^{-1}$ taken between 1996 and 2007 with the ZEUS detector, the cross section of exclusive Upsilon production in the di-muon decay channel has been measured as a function of W and Q$^2$. The results are consistent with the predictions of the QCD models: two-gluon exchange as calculated by MNRT (Martin-Nockles-Ryskin-Teubner) and non-relativistic QCD NLO calculations.
The feasibility of a measurement of the $|t|$ dependence of the cross section is discussed, where $|t|$ is the absolute value of the 4-momentum transfer to the proton, as well as an extension of the measurement to inelastic Upsilon production as function of the event inelasticity $z$.