Abstract. The authors analyse certain realizations of the rotation group in which half-integer representations appear, even though he employs scalar fields only. This angular momentum is interpreted as being purely orbital, and is shown to apply only to massless particles. He discusses the double-valued nature of these representations, including transformation properties of the spinors, which are formed only from space coordinates x and delta / delta x. He describes also position and momentum operators which can be defined.

Print publication: Issue 4 (April 1977)