Indexed on: 23 Oct '07Published on: 23 Oct '07Published in: Il Nuovo Cimento B (1971-1996)
Corben and Schwinger have introduced a parameter λ in the tensorial equation of Proca, in order to have an arbitrary gyromagnetic ratiog=1+λ. In the nonrelativistic approximation, an intrinsic electric-quadrupole moment appears in their theory and the coefficient of the term with divE, in the Hamiltonian, is not correct. The matricial form of the theory suggests another formula, analogous to this of the spin-1/2 particle. In the nonrelativistic approximation one has then no electric-quadrupole moment and the coefficient of the term with divE is correct. One may also, in the new theory, introduce an electric-quadrupole moment chosena priori, in the same manner as Young and Bludman did for the Corben-Schwinger theory.