Electromagnetic Properties of a Charged Vector Meson

A systematic study is made of the electromagnetic properties of charged vector mesons. The various formalisms used to describe charged particles of spin 1 are compared, and a new first-order formulation of the Stückelberg theory is developed. For the most general first-order Proca Lagrangian, subject to the usual symmetry requirements we eliminate the redundant components to obtain a Hamiltonian formulation. The theory is interpreted in the nonrelativistic limit, and the terms corresponding to spin-orbit coupling and electric quadrupole-moment interaction are identified. The analogy to spin-½ theory has led us to consider spin equations of motion which agree with the quantum-mechanical equations to order $m^{-2\mathrm{}}$.