We study the production of prompt photons at high energy in the framework of the k_T-factorization approach. The amplitude for production of a single photon associated with quark pair in the fusion of two off-shell gluons is calculated. Theoretical results are compared with the Tevatron data.
In the framework of the k_T-factorization approach, the production and polarization of Upsilon mesons at the Fermilab Tevatron is considered, and a comparision of the calculated double differential distributions and spin alignment parameter $alpha$ w
ith the D0 experimental data is shown. We argue that measuring the double differential cross section and the polarization of upsilonium states can serve as a crucial test discriminating two competing theoretical approaches to the parton dynamics in QCD.
In the framework of the k_t-factorization approach, the production of $Upsilon mesons at the Fermilab Tevatron and CERN LHC is considered, and the predictions on the spin alignment parameter $alpha$ are presented. We argue that measuring the polariza
tion of quarkonium states can serve as a crucial test discriminating two competing theoretical approaches to parton dynamics in QCD.
