Measurement of the $e^+e^-\to K_SK_L$ cross section near the $\phi(1020)$ resonance with the SND detector

TL;DR

This paper reports a precise measurement of the $e^+e^- o K_SK_L$ cross section near the $\,phi(1020)$ resonance using the SND detector, providing detailed resonance parameters with low systematic uncertainty.

Contribution

The study presents the first measurement of the $e^+e^- o K_SK_L$ cross section in the 1000-1100 MeV range with high precision and determines key resonance parameters from the energy dependence.

Findings

Cross section measured with 0.9% systematic uncertainty.

Mass and width of the $\,phi$ meson determined.

Product of branching fractions calculated from fit.

Abstract

The cross section for the $e^+e^-\to K_SK_L$ process is measured in the center-of-mass energy range from 1000 MeV to 1100 MeV in the experiment with the SND detector at the VEPP-2000 $e^+e^-$ collider. The measurement is carried out in the $K_S\to 2\pi^0$ decay mode. Data with an integrated luminosity of 20 pb$^{-1}$ recorded in 2018 at 18 energy points are used in the analysis. The systematic uncertainty in the measured cross section at the maximum of the $\phi$ resonance is 0.9%. The mass, width of the $\phi$ meson, and the product of the branching fractions $B(\phi\to K_SK_L)B(\phi\to e^+e^-)$ are determined from the fit to the cross-section energy dependence.