A precise new KLOE measurement of $F_\pi$ with ISR events and determination of $\pi\pi$ contribution to $a_\mu$ for [0.35,0.95] GeV$^2$

TL;DR

The paper reports a new precise measurement of the pion form factor using ISR events at KLOE, improving the accuracy of the $$ contribution to the muon anomalous magnetic moment in the specified energy range.

Contribution

It introduces a more precise determination of the pion form factor and the $$ contribution to $a_$ using ISR at KLOE, with reduced systematic uncertainties.

Findings

Reduced systematic uncertainty in the pion form factor measurement.

More accurate estimate of the $$ contribution to $a_$ in [0.35,0.95] GeV$^2$.

Enhanced precision over previous KLOE results.

Abstract

The KLOE experiment at the DA$\Phi$NE $\phi$-factory has performed a new precise measurement of the pion form factor using Initial State Radiation events, with photons emitted at small polar angle. Results based on an integrated luminosity of 240 pb$^{-1}$ and extraction of the $\pi\pi$ contribution to $a_\mu$ in the mass range [0.35,0.95] GeV$^2$ are presented, the systematic uncertainty is reduced with respect to the published KLOE result.