Tetramixing of vector and pseudoscalar mesons: A source of intrinsic   quarks
  The tetramixing of pseudoscalar mesons $\pi$-$\eta$-$\eta'$-$\eta_c$ and vector mesons $\omega$-$\rho$-$\phi$-$J/\psi$ are studied in the light-cone constituent quark model, and such mixing of four mesons provides a natural source for the intrinsic charm $c\bar{c}$ components of light mesons. By mixing with the light mesons, the charmonium states $J/\psi$ and $\eta_c$ could decay into light mesons more naturally, without introducing gluons or a virtual photon as intermediate states. Thus, the introduction of light quark components into $J/\psi$ is helpful to reproduce the new experimental data of $J/\psi$ decays. The mixing matrices and the $Q^2$ behaviors of the transition form factors are also calculated and compared with experimental data. 
Tao Peng, Bo-Qiang Ma
hep-ph hep-ex