Measurement of the Cross Section for $e^{+}e^{-}\to$ hadrons at Energies from 2.2324 to 3.6710 GeV

TL;DR

This paper reports precise measurements of the ratio of hadronic to muonic cross sections in electron-positron collisions across a range of energies, improving the accuracy of fundamental particle interaction data.

Contribution

The study provides new, high-precision measurements of the $R$ ratio at multiple energies, enhancing the existing data set for electron-positron annihilation processes.

Findings

Uncertainties less than 3.0%, dominated by systematics

14 energy points measured between 2.2324 and 3.6710 GeV

Improved precision over previous measurements

Abstract

Based on electron-positron collision data collected with the BESIII detector operating at the Beijing Electron Positron Collider II storage rings, the value of $R\equiv\sigma(e^{+}e^{-}\to$hadrons)/$\sigma(e^{+}e^{-}\to\mu^{+}\mu^{-})$ is measured at 14 center-of-mass energies from 2.2324 to 3.6710 GeV. The resulting uncertainties are less than $3.0\%$, and are dominated by systematic uncertainties.