Measurement of the cross section of $e^+e^-\rightarrow\Xi^{-}\bar\Xi^{+}$ at center-of-mass energies between 3.510 and 4.843 GeV

TL;DR

This study measures the cross sections and form factors of the process $e^+e^- ightarrow ext{Xi}^- ext{Xi}^+$ across energies 3.510 to 4.843 GeV, observing evidence for $ ext{psi}(3770)$ decay and setting limits for other states.

Contribution

First measurement of the cross sections and form factors for $e^+e^- ightarrow ext{Xi}^- ext{Xi}^+$ over a wide energy range, including evidence for $ ext{psi}(3770)$ decay.

Findings

Evidence for $ ext{psi}(3770) ightarrow ext{Xi}^- ext{Xi}^+$ with 4.5$\sigma$ significance.

No significant signals for other charmonium(-like) states' decays to $ ext{Xi}^- ext{Xi}^+$.

Upper limits set for branching fractions and electronic widths of several states.

Abstract

Using $e^+e^-$ collision data corresponding to a total integrated luminosity of 12.9 $fb^{-1}$ collected with the BESIII detector at the BEPCII collider, the exclusive Born cross sections and the effective form factors of the reaction $e^+e^-\rightarrow\Xi^{-}\bar\Xi^{+}$ are measured via the single baryon-tag method at 23 center-of-mass energies between 3.510 and 4.843 GeV. Evidence for the decay $\psi(3770)\rightarrow\Xi^{-}\bar\Xi^{+}$ is observed with a significance of 4.5$\sigma$ by analyzing the measured cross sections together with earlier BESIII results. For the other charmonium(-like) states $\psi(4040)$, $\psi(4160)$, $Y(4230)$, $Y(4360)$, $\psi(4415)$, and $Y(4660)$, no significant signal of their decay to $\Xi^-\bar \Xi^+$ is found. For these states, upper limits of the products of the branching fraction and the electronic partial width at the 90% confidence level are provided.