Transition form factors [formula omitted], rare decays [formula omitted] and muon g–2

Abstract

Measuring the muon anomalous magnetic moment g − 2 and the rare decays of light pseudoscalar mesons into a lepton pair P → l + l − serve as important tests of the standard model. To reduce the theoretical uncertainty in the standard model predictions, the data on the transition form factors of light pseudoscalar mesons play a significant role. Recently, new data on the behavior of these form factors at large momentum transfer were supplied by the BABAR collaboration. We comment on the (in)consistency of these data with perturbative QCD expectations and their influence on the rare decays.