U(2) AS THE ELECTROWEAK GAUGE GROUP

Using the fiber bundle formalism, the consequences of taking U(2) instead of SU(2)XU(1) as the electroweak gauge group are studied. This choice motivates using electric charge as the defining characteristic of particles: isospin and hypercharge quantum numbers are not assigned to particles. This in turn leads to a definition of matter fields in which quarks and leptons transform by the same U(2) representation; the representation being determined by electric charge quantum numbers only. As a result, all matter fields have equivalent coupling constants. Indeed, in this model, quarks have integer charge. Nevertheless, the quark and lepton currents as well as the gauge boson mass ratio are identical with the Standard Model predictions.