Theory of avoided level-crossing relaxation dynamics for axial muonated radicals

Abstract

A calculation encompasing the dynamics of rotational motion, electron spin relaxation and chemical reactions at an avoided level crossing resonance (ALCR) of muonated radicals with axial hyperfine anisotropy is presented. The main emphasis is directed toward the rotational diffusive motion, assumed to be isotropic, which is treated with the stochastic Liouville formalism. Inter-resonance interactions, electron and chemical relaxation effects are incorporated using a multistate version of the strong collision model, derived from the above formalism in the appropriate spin space. A central finding of the calculation concerns the role of the inter-resonance interactions. It will be shown that over the range where dynamical mechanisms broaden the ΔM = 1 ALCR line to the extent that there is overlap with the ΔM = 0, 2 lines, then these transitions are strongly supressed.