Explicit expression for the intensity tensor for 3/2-1/2 transitions and solution of the ambiguity problem in Mossbauer spectroscopy

Analytical expressions for the intensity tensor in the case of 3/2-1/2 nucl ear transitions are obtained and the properties of the trace, symmetric and antisymmetric parts of the intensity tensor for a single transition are di scussed. It is shown that in the principal axis system of the symmetric par t of the intensity tensor the angular dependence of absorption of the circu larly polarized resonant radiation depends essentially on only one paramete r-the maximal degree of circular polarization. The latter parameter is dire ctly connected with the antisymmetric part of the intensity tensor. It is s hown that the so-called ambiguity problem, including the sign of the hyperf ine magnetic field, can be solved by measuring the antisymmetric part using circularly polarized radiation. Some values typical in circular polarimetr y can be measured in a standard experiment and vice versa. Explicit express ions for the line intensities of the powdered absorber are given in the gen eral case of mixed transitions. The symmetry of the shape of the spectra wi th different signs of the electric field is explained. An experiment is pro posed in which all parameters of the I = 3/2 spin Hamiltonian can be unambi guously determined.