Diffractive production of vector mesons in Deep Inelastic Scattering within k_t-factorization approach

Abstract

In this work we give a theoretical description of the elastic vector meson production in diffractive DIS developed within the k_t-factorization formalism. Since the k_t-factorization scheme does not require large values of Q²+m_V², we conduct an analysis that is applicable to all values of Q² from photo- up to highly virtual production of vector mesons.<br /> The basic quantity in this approach - the unintegrated gluon structure function - was for the first time extracted from the experimental data on F_2p, thoroughly investigated, and consistently used in the vector meson production calculation.<br /> Moreover, by limiting ourselves to the lowest Fock state of the vector meson, we were able to construct in a closed form the theory of spin-angular coupling in the vector meson. This allowed us for the first time to address the production of a vector meson in a given spin-angular state. We performed an extensive analytical and numerical investigation of the properties of 1S, 2S, and D-wave vector meson production reactions.<br /> Treating the physical ground state vector mesons as purely 1S states, we observed a good overall agreement with all available experimental data on vector meson production. For the excited states, our analysis predicts a picture which is remarkably different from 1S-state, so that such reactions can be regarded as potential sources of new information on the structure of excited states in vector mesons.