DOI 10.1007/s100529800740
High precision tests of QED and physics beyond
the standard model
Rafel Escribano - Eduard Massó
Grup de Física Teòrica and IFAE, Edifici Cn,
Universitat Autònoma de Barcelona,
E-08193 Bellaterra, Spain
(e-mail: escribano@ifae.es, masso@ifae.es)
Received: 2 July 1997 / Published online: 20 February 1998
Abstract
We study the four most significant high precision observables
of QED --the anomalous electron and muon magnetic moments,
the hydrogen Lamb shift and muonium hyperfine splitting--
in the context of 
gauge-invariant effective
Lagrangians. The agreement between the theoretical predictions
for these observables and the experimental data
places bounds on the lowest dimension operators of the
effective Lagrangians. We also place bounds on such effective
operators using other experimental data.
Comparison of the two types of bounds allows us to discuss
the potential of each one of the four high precision observables
in the search for physics beyond the Standard Model.
We find that the anomalous electron and muon magnetic moments are
sensitive to new physics while the hydrogen Lamb shift and muonium
hyperfine splitting are not.
Copyright Springer-Verlag
