
%0 Journal Article
%A Swan, P 
%T On the Accuracy of the Tan hl Distorted Wave Approximation for Scattering Phase-Shifts
%J Australian Journal of Physics
%D 1963/06/01
%V 16
%N 2
%P 177-184
%K 
%R https://doi.org/10.1071/PH630177
%U https://www.publish.csiro.au/paper/PH630177 
%X The distorted wave approximation for tan ?l involves a wave function distorted from its asymptotic form at r ® 8 by a form factor g1(r). Schwinger's variational principle is adapted to show that increasing the number of variable parameters in g1(r) does not necessarily improve the firs 
