Why are those darn J = 3/2+ states invisible?

In a previous paper 1 there were two parts. The first part had to do with a state of pure seniority in the g[Formula: see text] shell. But here we focus on the second part in which the splitting E (21/2[Formula: see text](3/2[Formula: see text] is discussed for [Formula: see text] and [Formula: see text] of the (g[Formula: see text]) configuration of semi-magic nuclei. These J values are the maximum and minimum ones for [Formula: see text]. These are seniority [Formula: see text] states. We note the complete absence of empirical data on [Formula: see text] states needed to make comparisons. We offer explanations.