Connected and Leading Disconnected Hadronic Light-by-Light Contribution to the Muon Anomalous Magnetic Moment with a Physical Pion Mass

• Published in: Physical review letters Vol. 118; no. 2; p. 022005
• Main Authors: Blum, Thomas, Christ, Norman, Hayakawa, Masashi, Izubuchi, Taku, Jin, Luchang, Jung, Chulwoo, Lehner, Christoph
• Format: Journal Article
• Language: English
• Published: United States 13.01.2017
• ISSN: 1079-7114
• DOI: 10.1103/PhysRevLett.118.022005

We report a lattice QCD calculation of the hadronic light-by-light contribution to the muon anomalous magnetic moment at a physical pion mass. The calculation includes the connected diagrams and the leading, quark-line-disconnected diagrams. We incorporate algorithmic improvements developed in our previous work. The calculation was performed on the 48^{3}×96 ensemble generated with a physical pion mass and a 5.5 fm spatial extent by the RBC and UKQCD Collaborations using the chiral, domain wall fermion formulation. We find a_{μ}^{HLbL}=5.35(1.35)×10^{-10}, where the error is statistical only. The finite-volume and finite lattice-spacing errors could be quite large and are the subject of ongoing research. The omitted disconnected graphs, while expected to give a correction of order 10%, also need to be computed.