Measurement of the Pion Form Factor in the Energy Range 1.04-1.38 GeV with the CMD-2 Detector

TL;DR

This paper reports a precise measurement of the pion electromagnetic form factor in the energy range 1.04-1.38 GeV using the CMD-2 detector, providing valuable data for understanding hadronic contributions to fundamental processes.

Contribution

It presents new high-precision measurements of the pion form factor in a specific energy range, improving the accuracy of previous data and aiding theoretical models.

Findings

Measured cross section for $e^+e^- o ext{pions}$ with 1.2-4.2% systematic error

Achieved statistical errors of 5-13% in the form factor measurement

Collected 995,000 collinear events including various lepton and pion pairs

Abstract

The cross section for the process $e^+e^-\to\pi^+\pi^-$ is measured in the c.m. energy range 1.04-1.38 GeV from 995 000 selected collinear events including 860000 $e^+e^-$ events, 82000 $\mu^+\mu^-$ events, and 33000 $\pi^+\pi^-$ events. The systematic and statistical errors of measuring the pion form factor are equal to 1.2-4.2 and 5-13%, respectively.