On calculation of the Weinberg angle in unified theories of strong, electromagnetic and weak interactions

The Weinberg angle formula for the arbitrary group G, interconnecting three interaction types is derived. G symmetry group embeds SUsub(3)sup(c) + SUsub(2) x Usub(1) as a subgroup so that all fermions (leptons and quarks) formed a part of G group multiplets, which results in certain limitations in number of quarks and leptons as well as their charges. The possibility of dynamic symmetry breakdown at the very small distances is discussed. The inverse problem is also discussed: setting any scheme of weak and electromagnetic interaction of ''light fermions'' as well as the Weinberg angle experimental value (sinsup(2)THETAsub(w) approximately 1/3) the ratios between Csub(i) (i = 1,2,3) coefficients determining hypercharge, isospin, charge and colour generators are established, which permits to obtain information on structure of the G symmetry ''great'' group