Data-driven results for light-quark connected and strange-plus-disconnected hadronic $g-2$ short- and long-distance windows

TL;DR

This paper provides data-driven estimates for specific components of the hadronic vacuum polarization relevant to the muon g-2, highlighting discrepancies with lattice results and the impact of recent experimental data on resolving these differences.

Contribution

It offers new data-driven determinations of light-quark-connected and strange-plus-disconnected contributions to the RBC/UKQCD windows, comparing them with lattice results and analyzing recent experimental data effects.

Findings

Significant discrepancies in light-quark-connected parts between data-driven and lattice results.

Good agreement for strange-plus-disconnected components between data-driven and lattice results.

Recent CMD-3 data can reconcile discrepancies in the light-quark-connected components.

Abstract

A key issue affecting the attempt to reduce the uncertainty on the Standard Model prediction for the muon anomalous magnetic moment is the current discrepancy between lattice-QCD and data-driven results for the hadronic vacuum polarization. Progress on this issue benefits from precise data-driven determinations of the isospin-limit light-quark-connected (lqc) and strange-plus-light-quark-disconnected (s+lqd) components of the related RBC/UKQCD windows. In this paper, using a strategy employed previously for the intermediate window, we provide data-driven results for the lqc and s+lqd components of the short- and long-distance RBC/UKQCD windows. Comparing these results with those from the lattice, we find significant discrepancies in the lqc parts but good agreement for the s+lqd components. We also explore the impact of recent CMD-3 $e^+e^-\to \pi^+\pi^-$ cross-section results, demonstrating that an upward shift in the $\rho$-peak region of the type seen in the CMD-3 data serves to eliminate the discrepancies for the lqc components without compromising the good agreement between lattice and data-driven s+lqd results.