Measurements of the Cross Section for e+e- -> hadrons at Center-of-Mass Energies from 2 to 5 GeV

TL;DR

This paper presents measurements of the ratio of hadronic to muonic cross sections in electron-positron collisions across energies from 2 to 5 GeV, providing valuable data for understanding strong interactions.

Contribution

It provides a comprehensive set of cross section measurements at multiple energies using an upgraded detector at BEPC, filling gaps in existing data.

Findings

Measured R values at 85 energies between 2 and 5 GeV

Enhanced precision over previous measurements

Data supports theoretical models of hadronic production

Abstract

We report values of $R = \sigma(e^+e^-\to {hadrons})/\sigma(e^+e^-\to\mu^+\mu^-)$ for 85 center-of-mass energies between 2 and 5 GeV measured with the upgraded Beijing Spectrometer at the Beijing Electron-Positron Collider.