Spin-matrix polynomial development of the hamiltonian for a free particle of arbitrary spin and mass

S. A. Williams, Iowa State University
J. P. Draayer, Iowa State University
T. A. Weber, Iowa State University


The Hamiltonian and other relevant physical operators for a free particle of arbitrary spin and mass, based upon the generalized Foldy-Wouthuysen transformation, are developed in terms of the spin-matrix polynomials. The general theory of these polynomials, given in an earlier paper, is reviewed briefly. It is a general feature of these expansions that the number of terms is determined by the spin of the particle, but the coefficients are spin-independent. The massless limit is examined in some detail and the invariant metric operator is discussed. © 1966 The American Physical Society.