The Hadronic Light-by-Light Contribution to Muon g-2: A Short Review

Abstract

I review the recent calculations and current status of the hadronic light-by-light scattering contribution to muon g-2. In particular, I discuss the main results obtained in a recent work together with Eduardo de Rafael and Arkady Vainshtein where we came to the estimate a^{\rm HLbL}_\mu = (10.5 +- 2.6) x 10^{-10}. How the two-photon physics program of low energy facilities can help to reduce the present model dependence is also emphasized.

Comments: 13 pages, 3 figures. Invited talk given at "Photon09, International Conference on the Structure and Interactions of the Photon" May 11-15 2009, DESY, Hamburg, Germany