Hoferichter, MartinColangelo, GilbertoHoid, Bai-LongKubis, BastianRuiz De Elvira Carrascal, JacoboSchuh, DominicStamen, DominikStoffer, Pete2024-04-022024-04-022023-10-180031-900710.1103/PhysRevLett.131.161905https://hdl.handle.net/20.500.14352/1025852023 Descuento SCOAPPuzzles in the determination of the hadronic-vacuum-polarization contribution currently impede a conclusive interpretation of the precision measurement of the anomalous magnetic moment of the muon at the Fermilab experiment. One such puzzle concerns tensions between evaluations in lattice QCD and using e+e- -> hadrons cross-section data. In lattice QCD, the dominant isospin-symmetric part and isospin-breaking (IB) corrections are calculated separately, with very different systematic effects. Identifying these two pieces in a data-driven approach provides an opportunity to compare them individually and trace back the source of the discrepancy. Here, we estimate the IB component of the lattice-QCD calculations from phenomenology, based on a comprehensive study of exclusive contributions that can be enhanced via infrared singularities, threshold effects, or hadronic resonances, including, for the first time, in the e+e- -> 3 pi channel. We observe sizable cancellations among different channels, with a sum that even suggests a slightly larger result for the QED correction than obtained in lattice QCD. We conclude that the tensions between lattice QCD and e+e- data therefore cannot be explained by the IB contributions in the lattice-QCD calculations.engAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/journal article1079-7114https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.161905https://arxiv.org/abs/2307.02532open access539.1Anomalous magnetic momentShort distance constraintsQuark mass dependenceBy light contributionVector meson massesPi-pi scatteringPair productionMuon G-2EquationE(+)E(-)Partículas2207 Física Atómica y Nuclear