The radial equation of a simple potential model has long been known to yield
an exponential decay law in lowest order (Breit-Wigner) approximation. We
demonstrate that if the calculation is extended to fourth order the decay law
exhibits the quantum Zeno effect. This model has further been studied
numerically to characterize the extra exponential time parameter which
compliments the lifetime. We also investigate the inverse Zeno effect.Comment: 16 pages, 2 tables, 3 figures, AMS-Te