ρ0-ω mixing in U(3)LxU(3)R chiral theory of mesons

In this paper, U(3)(L)xU(3)(R) chiral theory of mesons is extended to the leading order in quark mass expansion in order to evaluate the rho(0) - omega 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, and 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 amplitude is obtained from the decay omega --> pi(+)pi(-). Furthermore, the constraints on the light quark mass parameters are extracted from the rho(0) - omega mixing and the :mesons masses, and the mass splitting of K*(892)-mesons is predicted.