We briefly review theoretical calculations for the pseudoscalar-vector meson
hyperfine splitting with no open flavor and also report a many body field
theoretical effort to assess the impact of chiral symmetry in the choice of
effective potentials for relativistic quark models. Our calculations predict
the missing eta_b meson to have mass near 9400 MeV. The radial excitation
ηc​(2S) is in agreement with the measurements of the BELLE and most
recently BABAR collaborations.Comment: European HEP conference proceedings (Aachen, July 2003). A few
typographical errors correcte