APPROACH TO THE SHIFTED 1/N EXPANSION FOR SPIN-1/2 RELATIVISTIC PARTICLE

A different approach to the shifted 1/N expansion method is developed to deal with the Dirac particle trapped in a spherically symmetric potential. The main aspects of our approach are to expand the energy term in a perturbative form and to determine the parameters involved without any approximation. While the formalism is developed for spin-1/2 particles in any spherically symmetric potential, it is applied to the Coulomb case for testing. The calculations are carried out to the third-order correction of the energy eigenvalue series