Anomalous quark-gluon chromomagnetic interaction and high energy $\rho$-meson electroproduction

Abstract

It is shown that existence of a large anomalous chromomagnetic moment of quark induced by non-perturbative structure of QCD leads to the additional contribution to exclusive $\rho$-meson electroproduction off proton target. The significant contribution coming from new type of quark-gluon interaction to the $\rho $-meson production cross section for both transversal and longitudinal polarization of virtual photon is found. Such non-perturbative contribution together with conventional perturbative two-gluon exchange allows us to describe the experimental data at low $Q^2$ for transversal polarization. However, in the longitudinal polarization case there is still some discrepancy with the data. The possible source of this deviation is discussed.