New precise measurement of the $e^+e^- \rightarrow \pi^+\pi^-(\gamma)$ cross section with BABAR

TL;DR

This paper reports a new, precise measurement of the $e^+e^- ightarrow \pi^+\pi^-(\gamma)$ cross section using BABAR data, which is crucial for improving the theoretical prediction of the muon's anomalous magnetic moment.

Contribution

It presents a new measurement of the $ ext{e}^+ ext{e}^- ightarrow ext{pi}^+ ext{pi}^-( ext{gamma})$ cross section with a larger dataset and an independent analysis method, enhancing the precision of the input for muon g-2 calculations.

Findings

Results are consistent with previous measurements.

Improved precision in the cross section measurement.

Contributes to reducing uncertainties in muon g-2 predictions.

Abstract

The BABAR experiment participates to the global endeavor for a precise prediction of the anomalous magnetic moment of the muon by evaluating the contribution from hadronic vacuum polarization, in particular through cross section measurements of hadronic final states from $e^+e^-$ collisions. After a first measurement in 2009 of the largest input that comes from the $e^+e^- \rightarrow \pi^+\pi^-(\gamma)$ cross section, we present preliminary results from a new study on 460 ${\rm fb}^{-1}$ of BABAR data, involving a blind and independent procedure. The results of the two analyses are shown to be consistent.