Determination of whether the number of zeros for transition-matrix elements is even or odd
Richard Henry Pratt, R. Y. Yin, Xiaoling Liang · Physical Review A · 1987
A general method is introduced for determining whether the number of zeros of a transition-matrix element (Cooper minima), considered as a function of energy, is even or odd. This method provides a general viewpoint for understanding the numerical observations and the well-known empirical rules about the existence of Cooper minima.