摘要
Based on the solution to the Bargmann Wigner equations, a direct derivation of the projection operator and Feynman propagator for a free massive particle of arbitrary spin is worked out. The projection operator constructed by Behrends and Fronsdal is re-deduced and confirmed, and simplified in the case of half-integral spin, the general commutation rules and Feynman propagator with additional non-covariant terms for a free massive particle with any spin are derived, and explicit expressions for the propagators for spins 3/2, 2, 5/2, 3, 7/2, and 4 are provided.
基金
The project supported partially by National Natural Science Foundation of China under Grant Nos.19947001,90103010,and 19991480
the Foundation of National Key Program for Basic Research of China under Grant No.2001CCB01000
the Doctoral Program Foundation
