rho(0)-omega mixing in U(3)(L)xU(3)(R) chiral theory of mesons

In this paper, U(3)(L)xU(3)(R) chiral theory of mesons is extended to the l eading order in quark mass expansion in order to evaluate the rho(0) - omeg a mixing. It is shown that the use of path integral method to integrate out the quark fields naturally leads to the rho(0) - omega mixing vertices, an d this mixing is entirely from the quark loop in this theory. The off-shell behaviour of the mixing amplitude is analyzed. The on-shell mixing amplitu de is obtained from the decay omega --> pi(+)pi(-). Furthermore, the constr aints on the light quark mass parameters are extracted from the rho(0) - om ega mixing and the :mesons masses, and the mass splitting of K*(892)-mesons is predicted.