Remarks on exclusive electroproduction of transversely polarized vector mesons - art. no. 074013

We discuss the electroproduction of light vector mesons from transversely p olarized photons. Here QCD factorization cannot be applied as shown explici tly in a leading-order calculation. It is emphasized that present infrared singular contributions cannot be regularized through phenomenological meson distribution amplitudes with suppressed end-point configurations. We point out that infrared divergences arise also from integrals over skewed nucleo n parton distributions. In a phenomenological analysis of transverse vector meson production model-dependent regularizations have to be applied. If th is procedure preserves the structure suggested by a lending-order calculati on of Feynman diagrams, one obtains contributions from nucleon parton distr ibutions and their derivatives. In particular, polarized gluons enter only through their derivative.