Cross section measurement of $e^{+}e^{-} \to K_{S}^{0}K_{L}^{0}$ at $\sqrt{s}=2.00-3.08~{\rm GeV}$

TL;DR

This study measures the cross sections of the process $e^{+}e^{-} o K_{S}^{0}K_{L}^{0}$ across 15 energy points between 2.00 and 3.08 GeV, revealing a resonant structure near 2.2 GeV with detailed parameters.

Contribution

First measurement of the cross sections for $e^{+}e^{-} o K_{S}^{0}K_{L}^{0}$ in this energy range, identifying a new resonance structure around 2.2 GeV.

Findings

Resonant structure observed at ~2.2 GeV with specific mass and width.

Cross sections consistent with BaBar results.

Product of radiative width and branching fraction measured.

Abstract

The cross sections of the process $e^{+}e^{-} \to K_{S}^{0}K_{L}^{0}$ are measured at fifteen center-of-mass energies $\sqrt{s}$ from $2.00$ to $3.08~{\rm GeV}$ with the BESIII detector at the Beijing Electron Positron Collider (BEPCII). The results are found to be consistent with those obtained by BaBar. A resonant structure around $2.2~{\rm GeV}$ is observed, with a mass and width of $2273.7 \pm 5.7 \pm 19.3~{\rm MeV}/c^2$ and $86 \pm 44 \pm 51~{\rm MeV}$, respectively, where the first uncertainties are statistical and the second ones are systematic. The product of its radiative width ($\Gamma_{e^+e^-}$) with its branching fraction to $K_{S}^{0}K_{L}^{0}$ ($Br_{K_{S}^{0}K_{L}^{0}}$) is $0.9 \pm 0.6 \pm 0.7~{\rm eV}$.