Experimental Test of Higher-Order QED and a Search for Excited Muon States

Abstract

The reactions $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-}\gamma \gamma$ and $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-}\gamma$ have been studied at $\sqrt{s}=29\mathrm{}$ GeV with the MAC detector at the SLAC storage ring PEP. The measured cross sections, charge asymmetry, and invariant-mass distributions are in good agreement with the predictions of QED theory. Limits are derived for the production of excited muon states.