  In the light of SU(3) flavor symmetry, the effective interaction Hamiltonian
in tensor form is obtained by virtue of group representation theory. The strong
and electromagnetic breaking effects are treated as a spurion octet so that the
flavor singlet principle can be utilized as the criterion to determine the form
of effective Hamiltonian for all charmonium two body decays. Moreover, a
synthetical nonet is introduced to include both octet and singlet
representations for meson description, and resorting to the mixing angle the
pure octet and singlet states are combined into the observable pseudoscalar and
vector particles, so that the empirically effective Hamiltonian can be obtained
in a concise way. As an application, by virtue of this scenario the relative
phase between the strong and electromagnetic amplitudes is studied for
vector-pseudoscalar meson final state. In data analysis of samples taken in
$e^+e^-$ collider, the details of experimental effects, such as energy spread
and initial state radiative correction are taken into consideration in order to
make full use of experimental information and acquire the accurate and delicate
results.

High Energy Physics - Phenomenology