Hadronic Contributions to R and g-2 from Initial-State-Radiation Data

TL;DR

This paper reviews recent efforts to improve the precision of the muon's anomalous magnetic moment prediction, focusing on the hadronic vacuum polarization contribution, especially the BaBar collaboration's initial-state radiation measurements for e+e- -> pi+pi-.

Contribution

It highlights new experimental results from BaBar using initial-state radiation to refine the hadronic contribution to g-2, reducing uncertainties in the theoretical prediction.

Findings

Improved measurement of e+e- -> pi+pi- cross section.

Reduced uncertainty in hadronic vacuum polarization contribution.

Enhanced precision in muon g-2 theoretical calculations.

Abstract

I review the recent efforts to improve the precision of the prediction of the anomalous moment of the muon, in particular of the hadronic contribution of the vacuum polarization, which is the contribution with the largest uncertainty. Focus is given to the recent result for e+e- -> pi+pi- by the BaBar collaboration, obtained using events with radiation in the initial state.