The asymptotics of spin distributions with good seniority

It is shown that the Ericson expression for the spin cutoff parameter corresponds to the classical limit of distinguishable particles. The quantum-mechanical limit of Hirst and Wybourne is improved in next to leading order. Their method is used to obtain the gaussian distribution parameters for single-level systems of good seniority, for both bosons and fermions. The extension to many levels is also given. (orig.)