  We consider the dependencies of spin asymmetries in the diffractive $J/\Psi$
and $Q \bar Q$ leptoproduction at HERA energies on the structure of the
pomeron-proton coupling. It is shown that it is difficult to study the spin
structure of the pomeron coupling with the proton from the $A_{ll}$ asymmetry.
The $A_{lT}$ asymmetry is an appropriate object for this investigation.

High Energy Physics - Phenomenology