On leave of absence from Dept. Theor. & Nucl. Phys., Saratov State University, Astrakhanskaya ul., 83, Saratov RUSSIA.

e-mail: [email protected]

Escuela de Física, Universidad Autónoma de Zacatecas
Antonio Dovalí Jaime s/n, Zacatecas 98068, ZAC., México
e-mail: [email protected]

Received 7 March 1997

The problems related to the choice of the spinorial basis in the (j,0)Ĺ(0,j) representation space are discussed. This choice is shown to have a profound significance in the relativistic quantum theory and for physical applications. From the methodological viewpoint, this fact is related to the important dynamical role which the space-time symmetries play for all kinds of interactions.

UDC 539.183.4
PACS numbers: 03.65.Pm, 11.30.Er