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

Abstract

We present the first data-driven result for $a_{\mu }^{\mathrm{win},\mathrm{lqc}}$, 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.

7 pages, 1 figure. References and additional discussion added. Version to appear in Phys. Rev. Lett