Asymptotic behavior of amplitudes for longitudinal-leptoquark processes and structure of the scaler sector in the minimal model involving four-color symmetry

Within the minimal model based on the four-color symmetry of quarks and lep tons of the Pati-Salam type, the asymptotic behavior of amplitudes for proc esses involving longitudinal leptoquarks (and W or Z bosons) is investigate d, together with the mechanism according to which the growth of these ampli tudes at high energies is suppressed by scalar fields. It is shown that, wi thin the Higgs mechanism of mass generation and of the mass splitting of qu arks and leptons, the four-color symmetry of quarks and leptons requires th at scalar-leptoquark doublets, scalar-gluon doublets, and an extra color-si nglet scalar doublet exist in addition to the standard Higgs doublet. (C) 2 001 MAIK "Nauka/Interperiodica".