2020/08/31 by Johan Bijnens, Nils Hermansson-Truedsson, Laetitia Laub +1 · 1 citation
Physics and Astronomy · #hep-ph
paper · pdf · doi:10.1007/jhep10(2020)203
53 pages, analytical results as FORM output included as results.txt, some references added, misprints corrected, one figure changed
arxiv created 2020/10/27 · arxiv updated 2020/12/02
The hadronic light-by-light contribution to the muon anomalous magnetic moment depends on an integration over three off-shell momenta squared (Qi2) of the correlator of four electromagnetic currents and the fourth leg at zero momentum. We derive the short-distance expansion of this correlator in the limit where all three Qi2 are large and in the Euclidean domain in QCD. This is done via a systematic operator product expansion (OPE) in a background field which we construct. The leading order term in the expansion is the massless quark loop. We also compute the non-perturbative part of the next-to-leading contribution, which is suppressed by quark masses, and the chiral limit part of the next-to-next-to leading contributions to the OPE. We build a renormalisation program for the OPE. The numerical role of the higher-order contributions is estimated and found to be small.