Laboratory study of the cosmic-ray muon lifetime

The cosmic-ray muon lifetime was measured with a variety of counters designed to study both the free and μ- capture lifetimes. The data were obtained using scintillation detectors and a lead glass detector. These data show the dependence of μ- capture on the atomic number of the chemical element in the detector. The Z dependence of the weak interaction capture process is discussed in terms of the familiar Fermi (ΔJ = 0) and Gamow--Teller (ΔJ = 1) decays. This experiment was designed for use in advanced undergraduate physics laboratories