Higher meson resonances in $\rho \to {\pi }^0{\pi }^0\gamma$ and $\omega \to {\pi }^0{\pi }^0\gamma$

Abstract

The role of higher meson resonances with spin 1 and 2 is investigated quantitatively in the decay processes of $\rho \to {\pi }^0{\pi }^0\gamma$ and $\omega \to {\pi }^0{\pi }^0\gamma$. Among the higher resonances, we find that the $f_2(1270)$ tensor meson can give a nontrivial contribution especially to the $\omega \to {\pi }^0{\pi }^0\gamma$ decay process. When the $f_2$ contribution is combined with the processes involving the vector and scalar meson intermediate states, a good agreement with the recent measurements is achieved for both decays. The effect of the $f_2(1270)$ is found to be sizable at the intermediate photon energies and may be verified by precise measurements of the recoil photon spectrum of the $\omega \to {\pi }^0{\pi }^0\gamma$ decay. The dependence of the decay widths on various models for the $\rho$-$\omega$ mixing in the literature is also investigated.

Comments: 16 pages, REVTeX, 6 figures, revised version, to appear in Phys. Rev. D