Data-driven determination of the light-quark connected component of the intermediate-window contribution to the muon $g-2$

TL;DR

This paper provides the first data-driven estimate of a specific component of the muon g-2 related to light-quark contributions, revealing a significant tension with recent lattice-QCD results and highlighting a discrepancy in the intermediate-window calculation.

Contribution

It introduces the first data-driven determination of the light-quark connected component of the intermediate-window contribution to muon g-2, contrasting with lattice-QCD results.

Findings

Data-driven result: (198.8 ± 1.1)×10^{-10}

Significant tension with lattice-QCD determinations

Highlights discrepancy driven by light-quark component

Abstract

We present the first data-driven result for $a_\mu^{\rm win,lqc}$, the isospin-limit light-quark connected component of the intermediate-window Hadronic-Vacuum-Polarization contribution to the muon anomalous magnetic moment. Our result, $(198.8\pm 1.1)\times 10^{-10}$, is in significant tension with eight recent mutually compatible high-precision lattice-QCD determinations, and provides enhanced evidence for a puzzling discrepancy between lattice and data-driven determinations of the intermediate window quantity, one driven largely by a difference in the light-quark connected component.