KLOE extraction of $a_\mu^{\pi\pi}$ in the mass range [0.35,0.95] GeV^2

TL;DR

This paper reports on the KLOE experiment's measurement of the pion form factor and its contribution to the muon's anomalous magnetic moment using e+e- collision data, with improved systematic uncertainties.

Contribution

It introduces a new extraction of $a_\mu^{\pi\pi}$ in the 0.35-0.95 GeV^2 range using two different photon selection schemes, enhancing previous analyses.

Findings

Consistent measurement of the $\pi\pi$ contribution to $a_\mu$.

Reduced systematic uncertainties compared to previous results.

Validation of the extraction method across different photon detection schemes.

Abstract

The KLOE Experiment at the $\phi$ factory DA$\Phi$NE, has measured the cross section $\sigma(e^+e^-\to\pi^+\pi^-\gamma)$ using two different selection schemes: requiring the photon emission at small polar angle and detecting the photon at large polar angle in the calorimeter. Using a theoretical radiator function we extract the pion form factor and obtain the $\pi\pi$ contribution to the anomalous magnetic moment of the muon. Results presented here come from the analysis of 240 pb^{-1} collected in 2002, with improved systematic uncertainty with respect to the published KLOE analysis. We also include an update of the previous analysis.