Measurements of $\psi(2S)$ decays into $\phi \pi^0$, $\phi \eta$, $\phi \eta^{'}$, $\omega \eta$, and $\omega \eta^{'}$

TL;DR

This study measures branching fractions of $oldsymbol{ ext{psi}(2S)}$ decays into specific vector and pseudoscalar meson pairs using BESII data, testing pQCD predictions and providing new decay rate limits.

Contribution

It provides the first measurements of certain $ ext{psi}(2S)$ decay modes and tests the pQCD 12% rule with new experimental data.

Findings

Measured branching fractions for $ ext{psi}(2S) o oldsymbol{ ext{phi}}oldsymbol{ ext{eta}}$, $oldsymbol{ ext{phi}}oldsymbol{ ext{eta}}^{'}$, and $oldsymbol{ ext{omega}}oldsymbol{ ext{eta}}^{'}$.

Set upper limits for $ ext{psi}(2S) o oldsymbol{ ext{phi}}oldsymbol{ ext{pi}}^{0}$ and $oldsymbol{ ext{omega}}oldsymbol{ ext{eta}}$ decays.

Results provide data to test perturbative QCD predictions.

Abstract

Decays of the $\psi(2S)$ into Vector plus Pseudoscalar meson final states have been studied with 14 million $\psi(2S)$ events collected with the BESII detector. Branching fractions of $\psi(2S) \rar\phi\eta$, $\phi\etap$, and $\omega\etap$, and upper limits of $\psi(2S) \rar \phi\piz$ and $\omega\eta$ are obtained: $B(\psi(2S) \rar\phi\eta) = (3.3\pm 1.1 \pm 0.5) \times 10^{-5}$, $B(\psi(2S) \rar\phi\etap) = (3.1\pm 1.4 \pm 0.7)\times 10^{-5}$, and $B(\psi(2S) \rar\omega\etap) = (3.2^{+2.4}_{-2.0} \pm 0.7) \times 10^{-5}$; and $B(\psi(2S) \rar\phi\piz) < 0.40 \times 10^{-5}$, and $B(\psi(2S) \rar\omega\eta) < 3.1 \times 10^{-5}$ at the 90 % C.L.. These results are used to test the pQCD ``12% rule''.