Quantum chromodynamics-vacuum and phenomenology of ''old'' mesons

The existing ideas on quantum chromodynamics vacuum lead to some non-trivial results for ''old'' mesons -particles constructed from u, d, s-quarks and (or) gluons without heavy quarks participation. A new classification of hadrons is suggested: by the character of interaction of quark and gluon constituents with vacuum fields. It appears that this interaction is not of universal character and substantially changes from hadron to hadron. In the bag model language this means the ''bag constant'' B depends on quark (gluon) hadron content and its quantum numbers. The relation to vacuum fields is characterized by a certain latent P parameter. The introduction of this parameter gives quantitative sense to quark-hadron and gluon-hadron duality. Duality intervals have been found in various channels. For example, in the O- gluon channel it appears to be great, approximately 6 GeV. The hadron phenomenology regularity is naturally explained. Zweig rule approximated SU (6) symmetry etc. Gluons are discussed in detail. Gluon states masses with various quantum numbers are estimated. A new formula for eta-meson mass is obtained