Exclusive processes $e^+e^-\to VP$ in $k_T$ factorization

Abstract

The exclusive processes $e^+e^-\to VP$, in the region of which the final state meson momentum is much larger than the hadronic scale $Λ_{QCD}$, are studied in the framework of PQCD approach based on the $k_T$ factorization. Including the transverse momentum distribution in the light cone wave functions, our results are consistent with the experimental measurements. According to our results, many processes have large enough cross sections to be detected at $\sqrt s=10.58$ GeV. The $s$ dependence of the cross section has been directly studied and our result indicates that the $1/s^3$ scaling is more favored than $1/s^4$. We also find that the gluonic contribution for the processes involving $η^{(')}$ is tiny.