Observation of Muon Trident Production in Lead and the Statistics of the Muon

Abstract

We have observed the production of muon tridents in lead with an effective cross section of 51 \ifmmode\pm\else\textpm\fi{} 7 nb per nucleus, in agreement with the predictions of quantum electrodynamics. This measurement is sufficiently accurate that the interference term due to the presence of two identical muons in the final state is seen. The size of the measured interference term is 1.15 \ifmmode\pm\else\textpm\fi{} 0.25 times the value predicted for Fermi statistics.