RT Journal Article
T1 Phenomenological estimate of isospin breaking in hadronic vacuum polarization
A1 Hoferichter, Martin
A1 Colangelo, Gilberto
A1 Hoid, Bai-Long
A1 Kubis, Bastian
A1 Ruiz De Elvira Carrascal, Jacobo
A1 Schuh, Dominic
A1 Stamen, Dominik
A1 Stoffer, Pete
AB Puzzles 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.
PB American Physical Society
SN 0031-9007
YR 2023
FD 2023-10-18
LK https://hdl.handle.net/20.500.14352/102585
UL https://hdl.handle.net/20.500.14352/102585
LA eng
NO 2023 Descuento SCOAP
NO Swiss National Science Foundation
NO German Research Foundation (DFG)
NO Ministerio de Economia y Competitividad (España)
DS Docta Complutense
RD 6 abr 2025