LXXXVI. Note on the analytic continuation of the S-matrix
N. G. van Kampen · The London Edinburgh and Dublin Philosophical Magazine and Journal of Science · 1951
Summary It is shown that methods which try to avoid the redundant poles are not likely to be successful. On the other hand, the analytic continuation of the S-matrix is an ill-defined procedure, which cannot be applied until more properties of the S-matrix are known. The redundant poles are caused by the use of the asymptotic expression of the wave function instead of its actual value and have no physical meaning.