MODERN PHYSICS LETTERS A, cilt.18, sa.12, ss.859-865, 2003 (SCI-Expanded)
The properties of new heavy mesons containing new heavy quarks have been investigated. As an example, the fourth SM family quarks and weak iso-singlet quarks predicted by E-6 GUT are considered. Production of these hadrons at TeV energy lepton colliders due to resonant formation of corresponding quarkonia have been analyzed.