Depolarization of NegativeμMesons

Abstract

The depolarization of negative $\mu$ mesons is discussed in terms of the processes occurring in the formation of $\mu$-mesonic atoms and the subsequent cascade to the ground state. The initial distribution of $\mu$ mesons in capturing states of carbon is deduced. The depolarization due to the capture process is derived in a fashion free of essentially all approximations. The only assumption involved is that the scattering cross section is such as to randomize the direction of motion prior to capture and this assumption is shown to be well fulfilled. The effect of radiative transitions in producing depolarization is determined with all possible dipole transitions taken into account. Only nuclei with zero spin are treated in detail. The Auger process is included in a schematic fashion which is sufficient for the purpose in hand. It is shown that both radiative and Auger transitions must be included in the discussion of the depolarization processes in the cascade. The theoretical results are compared with experiment, and from the comparison it is concluded that the observed facts are well accounted for.