THE DEPOLARIZATION OF NEGATIVE MU MESONS (thesis)

Abstract

>A discussion of the observed polarizaticn of the negative mu mesons is presented. It is shown that the depolarization of the negative mu mesons may be explained by consideration of the processes attendant to the formation of mumesic atoms. The depolarization occurs when the mu mesons are initially captured into a highly excited bound state and in the subsequent transitions. As an essential preliminary to deducing the depolarization on capture the distribution of the mu mesons in initial states of the capturing atoms is determined. This distribution depends on the rate at which the mu mesons lose energy in the stopping process. The depolarization in the initial capturing event is due to the spin-orbit coupling; however, the extent of the depolarization in capture is strongly conditioned by the scattering preceding capture. It is shown that the mu mesons may be regarded as having random direction when they are captured. In the cascade subsequent to capture both radiative and Auger transitions are important. These are treated in an adequate manner and the final polarization of the mu mesons is derived theoretically. The circular polarization of the x rays emitted in the last stage of the cascade is discussed. It is found that the negative mu mesons should retain a polarization of 0.133 in the ground state of mu-mesic carbon. The results obtained are compared with the best experimental data available. The excellent agreement and the unambiguous nature of tbe analysis presented indicate the validity of the basic assumption that the mu mesons interact with matter in just the same manner as an electron. (auth)