  We discuss consequences of the models of "tensorial pomeron" and "vectorial
pomeron" for exclusive diffractive production of scalar and pseudoscalar mesons
in proton-proton collisions. Diffractive production of $f_{0}(980)$,
$f_{0}(1370)$, $f_{0}(1500)$, $\eta$, and $\eta'(958)$ mesons is discussed.
Different pomeron-pomeron-meson tensorial coupling structures are possible in
general. In most cases two lowest orbital angular momentum - spin couplings are
necessary to describe experimental differential distributions. For $f_{0}(980)$
and $\eta$ production reggeon-pomeron, pomeron-reggeon, and reggeon-reggeon
exchanges are included in addition, which seems to be necessary at relatively
low energies. The theoretical results are compared with the WA102 experimental
data. Correlations in azimuthal angle between outgoing protons, distributions
in rapidities and transverse momenta of outgoing protons and mesons, in a
special "glueball filter variable", as well as some two-dimensional
distributions are presented. We discuss differences between results of the
vectorial and tensorial pomeron models. We show that high-energy central
production, in particular of pseudoscalar mesons, could provide crucial
information on the spin structure of the soft pomeron.
