Measurement of the $e^+e^- \to K^+ K^- \pi^0$ cross section with the SND detector

TL;DR

This paper reports a precise measurement of the $e^+e^- o K^+K^- o ext{pi}^0$ cross section using the SND detector, revealing the dominant intermediate states and interference effects in the energy range 1.28 to 2 GeV.

Contribution

First measurement of the $e^+e^- o K^+K^- ext{pi}^0$ cross section with the SND detector, including analysis of intermediate states and interference effects.

Findings

Dominant contribution from $K^{ ext{*}}(892)K$ intermediate state.

Measured cross section for $ ext{phi} ext{pi}^0$ state.

Interference significantly affects the cross section below 1.7 GeV.

Abstract

The process $e^+e^-\to K^+K^-\pi^0$ is studied with the SND detector at the VEPP-2000 $e^+e^-$ collider. Basing on data with an integrated luminosity of 26.4~pb$^{-1}$ we measure the $e^+e^-\to K^+K^-\pi^0$ cross section in the center-of-mass energy range from 1.28 up to 2 GeV. The measured mass spectrum of the $K\pi$ system indicates that the dominant mechanism of this reaction is the transition through the $K^{\ast}(892)K$ intermediate state. The cross section for the $\phi\pi^0$ intermediate state is measured separately. The SND results are consistent with previous measurements in the BABAR experiment and have comparable accuracy. We study the effect of the interference between the $\phi\pi^0$ and $K^\ast K$ amplitudes. It is found that the interference gives sizable contribution to the measured $e^+e^- \to \phi \pi^0\to K^+K^-\pi^0$ cross section below 1.7 GeV.