Measurement of $e^{+}e^{-} \to K^{+}K^{-}\pi^{0}$ cross section and observation of a resonant structure

TL;DR

This study measures the cross section of the process $e^{+}e^{-} o K^{+}K^{-} o \pi^{0}$, performs a partial-wave analysis, and observes a resonant structure consistent with the $ ext{phi}(2170)$, enhancing understanding of this state.

Contribution

First measurement of the $e^{+}e^{-} o K^{+}K^{-} o \pi^{0}$ cross section with a detailed partial-wave analysis and observation of a resonance consistent with $ ext{phi}(2170)$.

Findings

Cross section measurements align with BaBar with improved precision.

Observation of a resonance at 2208 MeV/$c^{2}$ with 7.6$\sigma$ significance.

Resonance parameters support identification as $ ext{phi}(2170)$.

Abstract

Based on $e^{+}e^{-}$ collision data collected by the BESIII detector at the BEPCII collider at center-of-mass energies from 2.000 to 3.080 GeV, a partial-wave analysis is performed for the process $e^{+}e^{-} \to K^{+}K^{-}\pi^{0}$. The Born cross section of the process $e^{+}e^{-} \to K^{+}K^{-}\pi^{0}$ and its subprocesses $e^{+}e^{-} \to \phi \pi^{0}$, $K^{*}(892)K$ and $K^{*}_{2}(1430)K$ are measured. The results for $e^{+}e^{-} \to K^{+}K^{-}\pi^{0}$ and $\phi \pi^{0}$ are consistent with the BaBar measurements and with improved precision. By analyzing the cross section, of the subprocesses $e^{+}e^{-} \to$ $K^{*}(892)K$ and $K^{*}_{2}(1430)K$, a structure with mass $M_R$ = (2208 $\pm$ 19 $\pm$ 24) MeV/$c^{2}$ and width $\Gamma_R$ = (168 $\pm$ 24 $\pm$ 39) MeV is observed with a combined statistical significance of 7.6$\sigma$. The measured resonance parameters suggest it can be identified as the $\phi(2170)$, thus the results provide valuable input to understand the internal nature of this state.