Measurement of the cross sections of $e^+e^-\to K^{-}\bar\Xi^{+}\Lambda/\Sigma^{0}$ at center-of-mass energies between 3.510 and 4.914 GeV

TL;DR

This study measures the cross sections of specific electron-positron collision processes involving strange baryons across a range of energies, revealing evidence for the $ ext{psi}(4160)$ resonance decaying into these particles for the first time.

Contribution

It provides the first evidence of $ ext{psi}(4160)$ decaying into $K^{-}ar{ extXi}^{+} extLambda$ with a significance of 4.4$\sigma$, and measures the cross sections at multiple energies.

Findings

Evidence for $ ext{psi}(4160)$ decay into $K^{-}ar{ extXi}^{+} extLambda$

Measured cross sections at 35 energy points

Determined resonance parameters and decay widths

Abstract

Using $e^+e^-$ collision data collected with the BESIII detector at the BEPCII collider at center-of-mass energies between 3.510 and 4.914GeV, corresponding to an integrated luminosity of 25 fb$^{-1}$, we measure the Born cross sections for the process $e^+e^-\to K^-\bar{\Xi}^+\Lambda/\Sigma^{0}$ at thirty-five energy points with a partial-reconstruction strategy. By fitting the dressed cross sections of $e^+e^-\to K^-\bar{\Xi}^+\Lambda/\Sigma^{0}$, evidence for $\psi(4160) \to K^{-}\bar\Xi^{+}\Lambda$ is found for the first time with a significance of 4.4$\sigma$, including systematic uncertainties. No evidence for other possible resonances is found. In addition, the products of electronic partial width and branching fraction for all assumed resonances decaying into $K^{-}\bar\Xi^{+}\Lambda/\Sigma^{0}$ are determined.