Why not an e fi l experiment ? An extended exercise for students studying introductory particle physics

We present an extended problem appropriate for students in a semester-long introductory elementary particle physics class. This problem requires them to synthesize concepts and investigative approaches learned throughout the class, directed toward answering the question of why muon-to-electron conversion experiments are proposed, but not electron-to-muon experiments. Although direct electron-to-muon decays are kinematically forbidden, the production of muons via the interaction of electron and photon beams is kinematically allowed, so why not propose such an experiment? In the analysis presented here, we set forth a model approach that guides students through exploration of the design of such a proposed experiment. As part of the discussion, we identify an obstacle that makes doing an experiment of this kind prohibitively difficult. VC 2014 American Association of Physics Teachers. [http://dx.doi.org/10.1119/1.4885795]