On the flavor mixing by a Light-Cone Hamiltonian and the isotopic spin in QCD

The structure of an effective light-cone Hamiltonian as recently derived is analyzed with emphasis on its prediction for flavor mixing in physical mesons. In a (perhaps over-simplified) model with one adjustable parameter, the empirical masses of all 25 pseudo-scalar mesons which are possible for 5 flavors are reproduced (almost) quantitatively. These results are coupled with explicit numerical estimates of flavor mixing. In the present approach, the well-known mass degeneracy of the pion triplet is caused by the mass degeneracy of the up and down quark.