The QCD spectrum: mixing, strong decays and the role of sea quarks

The light hadron spectrum as computed in nonperturbative QCD is reviewed and compared to lattice data and experiment. The mixing of mesons, hybrids and glueballs is calculated in the Field Correlator Method. The strong decay mechanisms are found out in the method and compared to the known phenomenological models. The role of sea quarks (unquenched approximation) is studied analytically using radially excited mesons as an example, and compared to experiment.