Review of recent leading-order hadronic vacuum polarization calculation

TL;DR

This paper reviews recent calculations of the leading-order hadronic vacuum polarization contribution to the muon g-2, highlighting uncertainties, recent results, and open issues in the field.

Contribution

It provides a comprehensive overview of recent leading-order hadronic vacuum polarization calculations using $e^+e^-$ and $ au$ data, emphasizing current challenges and uncertainties.

Findings

The hadronic contribution has the largest uncertainty in muon g-2 predictions.

Discrepancies of about 3.6 and 2.4 standard deviations exist between theory and experiment.

Open issues remain in refining the calculation and understanding the data used.

Abstract

The leading-order hadronic contribution to the muon magnetic moment anomaly $a_\mu\equiv (g_\mu-2)/2$, calculated using a dispersion integral of $e^+e^-$ annihilation data and $\tau$ data, is briefly reviewed. This contribution has the largest uncertainty to the predicted value of $a_\mu$, which differs from the direct measurement by $\sim 3.6 (2.4)$ standard deviations for the $e^+e^- (\tau)$ based analysis. Recent results and main open issues on the subject are discussed.