Approach to the shifted 1/N expansion for the Klein - Gordon equation

Abstract

A different approach to the shifted 1/N expansion technique is developed to deal with the Klein-Cxordon particle trapped in a spherically symmetric potential. Properly modifying the definition of the perturbative expansion of the energy eigenvalue, and without making any approximation in the determination of the parameters involved, we obtain suSciently good results compared with the exact ones for the Coulomb problem. The calculations are carried out to the second-order correction of the energy series.