SHADOWING CORRECTIONS IN DIFFRACTIVE QCD LEPTOPRODUCTION OF VECTOR-MESONS

The formulae for shadowing corrections in deep inelastic leptoproducti on of vector mesons are presented. These formulae are also applicable for photoproduction of vector mesons constituted of heavy quarks. Our results are conveniently presented by the definition of a damping fact or giving the reduction of the calculated cross sections due to shadow ing. Our calculated cross sections are compared with those obtained wi th no shadowing and with the available experimental data including the recent data from HERA. We have also investigated the importance of sh adowing on the relationship between partial derivative F-2(Q(2),x)/par tial derivative ln Q(2) and the cross section for virtual photoproduct ion of vector mesons. A discussion of shadowing corrections to the pro ton's gluon density is presented and numerical estimates are given.