Loop Contribution to ρ − ω Mixing and Mass Splitting

We study the self-energy amplitudes for the ρ − ω meson system produced by an effective field theory model at the quark level characterized by a finite range quark-quark interaction and an isospin breaking bare quark mass difference m u − m d. Dynamical effects associated with confinement and dressing of quarks and the finite size of the produced ¯ qq meson modes are treated. Parameters of this approach, previously constrained by soft pion physics, are here supplemented in a minimal way to reproduce m ω and g ρππ. Calculations are carried out up to the one pion loop level and the predictions for ρ 0 − ω mixing, mass splitting, the ρ width and the symmetry breaking ωππ coupling constant and form factor are presented. The contribution of the direct ω → ππ process relative to the ω → ρ → ππ process is discussed within this model.