Measurement of $e^{+}e^{-}\to\phi\eta'$ cross sections at center-of-mass energies from 3.508 to 4.951 GeV and search for the decay $\psi(3770)\to\phi\eta'$

TL;DR

This study precisely measures the e+e- to phi eta' cross sections across a range of energies, compares the results with theoretical predictions, and searches for a rare decay mode of psi(3770) but finds no significant signal.

Contribution

It provides high-precision cross section measurements over a broad energy range and sets an upper limit on the branching fraction of a rare decay mode.

Findings

Cross sections decrease with energy following s^{-n/2} with n=4.35±0.14.

Results agree with the Nambu-Jona-Lasinio model prediction.

No significant signal observed for the psi(3770) to phi eta' decay.

Abstract

The cross sections of the $e^{+}e^{-}\to\phi\eta'$ process at center-of-mass energies from 3.508 to 4.951 GeV are measured with high precision using 26.1 fb$^{-1}$ data collected with the BESIII detector operating at the BEPCII storage ring. The cross sections are of the order of a few picobarn, and decrease as the center-of-mass energy increases as $s^{-n/2}$ with $n=4.35\pm 0.14$. This result is in agreement with the Nambu-Jona-Lasinio model prediction of $n=3.5\pm 0.9$. In addition, the charmless decay $\psi(3770)\to\phi\eta'$ is searched for by fitting the measured cross sections, yet no significant signal is observed. The upper limit of ${\cal B}(\psi(3770)\to\phi\eta')$ at the 90\% confidence level is determined to be $2.3\times 10^{-5}$.