Light vector meson photoproduction at large t

We have studied in perturbative QCD all independent helicity amplitudes des cribing the photoproduction of Light vector mesons at large t. We found a n ew hard production mechanism which is related to the possibility for a real photon to fluctuate into a massless q (q) over bar pair in a chiral-odd sp in configuration. Each helicity amplitude is given as a sum of a usual chir al-even contribution (when the helicities of quark and antiquark are antipa rallel) and this additional chiral-odd part (where the helicities of quark and antiquark are parallel). The chiral-odd contribution is large, it leads to a dominance of the non spin-flip amplitude in a very broad region of in termediately high \t\. All amplitudes are expressed in terms of short dista nce asymptotics of the light-cone wave functions of vector meson (photon). We demonstrate that for each helicity amplitude there exists a soft non-fac torizable contribution, We give arguments that for dominant non spin-flip h elicity amplitude the relative contribution of the soft nonfactorizable int eractions is numerically not large. (C) 2000 Elsevier Science B,V. All righ ts reserved.