On flavor mixing by an effective Light-Cone QCD-Hamiltonian

The $\uparrow \downarrow$-model has produced the physical masses of all flavor-asymmetric mesons like the ${\pi }^{\pm }$ or the ${\rho }^{\pm }$. Can the same model also account for the flavor-symmetric mesons like the ${\pi }^0$ or the ${\rho }^0$? – By adjusting one parameter in a $5\times 5$-matrix, the $\pi$-$\eta$ degeneracy is lifted and the $\eta -{\eta }^{\mathrm{\prime }}$ splitting falls into the right ball park. The isospin triplets for pions and rhos are caused the mass-degeneracy of the up and down quark.