Journal of Mathematical Physics
Mass dependence of Schrödinger wavefunctions
C. N. Leung, Jonathan L. Rosner
Abstract
It is shown that for nonrelativistic central potentials of specific forms, the bound state wavefunctions u (r) have the property that G (r) ≡ℱ r0dx u (x)(∂u (x)/∂μ) ⩽0 for all r. Here μ is the reduced mass. Thus, for such potentials, the probability that a particle lies within a spherical shell of radius r is a monotonically increasing function of μ. The forms for which this property has been established are (a) V (r) =Crε, −2<ε<∞; (b) V (ir) =C lnr, and (c) S waves in the potential, V (r) =−V0 (0⩽r<a), V (r) =0 (a⩽r<∞). For all monotonically increasing potentials, G (r) ≳0 for nodeless states. It is shown explicitly that G (r) cannot be nonnegative for all bound states in an arbitrary monotonically increasing potential. The question remains open regarding the widest class of potentials for which G (r) is nonnegative for all bound states.