High sensitivity tests of the standard model for electroweak interactions. [Lepton-family-number-violating decay; Michel [rho] parameter

Abstract

The work done on this project was focused on two LAMPF experiments. The MEGA experiment, a high-sensitivity search for the lepton-family-number-violating decay [mu] [yields] e [gamma] to a sensitivity which, measured in terms of the branching ratio, BR = [[mu] [yields] e [gamma]]/[[mu] [yields] ev[sub [mu]] v[sub e]] [approximately] 10[sup [minus]13], is over two orders of magnitude better than previously reported values. The second is a precision measurement of the Michel [rho] parameter from the positron energy spectrum of [mu] [yields] ev[sub [mu]] v[sub e] to test the V-A theory of weak interactions. The uncertainty in the measurement of the Michel [rho] parameter is expected to be a factor of three lower than the present reported value.