We discuss the hadronic light-by-light scattering contribution to the muon anomalous magnetic moment aμ1b1, paying particular attention to the consistent matching between the short- and the long-distance behavior of the light-by-light scattering amplitude. We argue that short-distance QCD imposes strong constraints on this amplitude overlooked in previous analyses. We find that accounting for these constraints leads to approximately 50% increase in the central value of aμ 1b1, compared to commonly accepted estimates (see, e.g., [M. Davier, S. Eidelman, A. Hocker, and Z. Zhang, Eur. Phys. J. C 31, 503 (2003).]). The hadronic light-by-light scattering contribution becomes aμ 1b1 = 136 (25) × 10-11, thereby shifting the standard model prediction closer to the experimental value.
|Original language||English (US)|
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|State||Published - Dec 2004|
Bibliographical noteFunding Information:
We are grateful to M. Voloshin for helpful discussions. This research is supported by the DOE under Contract Nos. DE-FG03-94ER-40833, DE-FG02-94ER408, and DE-FG03-94ER40833.