  In this article we prove spin statistics theorem for arbitrary massive (A, B)
field in a representation theoretic manner. General Gamma matrices are
introduced, and explicit forms for low spin are calculated. Spin sums and
twisted spin sums are introduced to prove spin statistics and derive field
equations respectively, and their relations are discussed. Klein Gordan
equation is just the condition on the 4-momentum. Dirac equation (or massive
Weyl equations) and Proca equation are shown to be examples of our general
field equation.
