# Cross section measurements of $e^{+}e^{-} \to K^{+}K^{-}K^{+}K^{-} $ and $ \phi K^{+}K^{-}$ at center-of-mass energies from 2.10 to 3.08 GeV

## TL;DR

This study measures the cross sections of specific electron-positron annihilation processes involving kaons at energies from 2.10 to 3.08 GeV, revealing an enhancement near 2.232 GeV close to the Lambda-antLambda threshold.

## Contribution

First measurement of these cross sections in this energy range, identifying an enhancement near 2.232 GeV and comparing energy dependence with related processes.

## Key findings

- Observation of an enhancement at 2.232 GeV near Lambda-antLambda threshold
- Different energy dependence compared to e+e- → φ π+π−
- Cross section measurements for e+e- → K+K−K+K− and φK+K−

## Abstract

We measure the Born cross sections of the process $e^{+}e^{-} \to K^{+}K^{-}K^{+}K^{-}$ at center-of-mass (c.m.) energies, $\sqrt{s}$, between 2.100 and 3.080 GeV. The data were collected using the BESIII detector at the BEPCII collider. An enhancement at $\sqrt{s}= 2.232$ GeV is observed, very close to the $e^{+}e^{-} \to \Lambda \overline{\Lambda}$ production threshold. A similar enhancement at the same c.m. energy is observed in the $e^{+}e^{-} \to \phi K^{+}K^{-}$ cross section. The energy dependence of the $K^{+}K^{-}K^{+}K^{-}$ and $\phi K^{+}K^{-}$ cross sections differs significantly from that of $e^{+}e^{-} \to \phi \pi^{+}\pi^{-}$.