Spin, statistics, and the spin quantization frame
The spin-statistics connection is derived in a simple manner under the postulates that (1) the state vectors are only superposed with the plus sign, and (2) not only a common spin quantization axis but a complete quantization frame has to be specified. This means that the orientation of the spin states in the plane normal to the quantization axis has to be specified. Before the state vectors can be superposed their spinor ambiguity has to be removed. This is achieved by relating the orientation angles by means of rotations in spin space and taking all rotations in the same sense. The minus sign for particles with half-integral spin then obtains by applying the above principles to transition-amplitude formulas. Relativity and quantum field theory are not involved.