Circular polarization of muonic x rays and origin of strange. mu. /sup -/ depolarization in Pd metal

The circular polarization of muonic x rays has been measured in order to investigate the mechanism of the unexpectedly fast depolarization of the negative muon in Pd metal as observed by the negative-muon spin-rotation method. A large circular polarization consistent with the maximal theoretical value was observed in both Pd and Cd metals, showing that the polarization is preserved up to the time the muon reaches the 1s atomic ground state.