Observation of the Exclusive Reaction e+e- -> phi eta at sqrt{s}=10.58 GeV

TL;DR

This paper reports the first observation of the e+e- to phi eta reaction at 10.58 GeV, measuring its cross section with high significance, providing new experimental data on this exclusive process.

Contribution

The study provides the first measurement of the e+e- to phi eta cross section at this energy, using data from the BaBar experiment, with detailed angular and invariant mass analysis.

Findings

Observation of e+e- to phi eta with 6.5 sigma significance.

Measured cross section of approximately 2.9 fb with uncertainties.

Provides experimental data for theoretical models of e+e- annihilation.

Abstract

We report the observation of $\e^+e^-\to \phi\eta$ near $\sqrt{s}$ = 10.58 GeV with 6.5 $\sigma$ significance in the $K^+K^-\gamma\gamma$ final state in a data sample of 224 $fb^{-1}$ collected by the BaBar experiment at the PEP-II $e^+e^-$ storage rings. We measure the restricted radiation-corrected cross section to be $\sigma(\e^+e^- \to \phi \eta) =$$2.1\pm 0.4 (\mathrm{stat})\pm 0.1(\mathrm{syst}) \mathrm{fb}$ within the range $|\cos\theta^*| < 0.8$, where $\theta^*$ is the center-of-mass polar angle of the $\phi$ meson. The $\phi$ meson is required to be in the invariant mass range of 1.008 $< m_{\phi} <$ 1.035 \gevcc. The radiation-corrected cross section in the full $\cos\theta^*$ range is extrapolated to be $2.9\pm 0.5 (\mathrm{stat})\pm 0.1(\mathrm{syst}) \mathrm{fb}$.