  Exploiting a set of generalized parton distributions (GPDs) derived from
analyses of hard exclusive leptoproduction of rho0, phi and pi+ mesons, we
investigate the omega spin density matrix elements (SDMEs) recently measured by
the HERMES collaboration. It turns out from our study that the pion pole is an
important contribution to omega production. It will be treated as a
one-particle exchange since its evaluation from the GPD E-tilde considerably
underestimates its contribution. As an intermediate step of our analysis we
extract the pi-omega transition form factor for photon virtualities less than 4
GeV^2. From our approach we achieve results for the omega SDMEs in good
agreement with the HERMES data. The role of the pion pole in exclusive rho0 and
phi leptoproduction is discussed too.
