S13-3D1 effective-range parameters of some realistic nucleon-nucleon potentials

We consider the P- and Q-shape parameters in the eigenphase and ‘‘bar’’ phase shift representations for the two Reid potentials and the more recent Moscow potential. The values of these parameters were obtained from integrals of the zero-energy wave function in a similar manner to that for the effective range. Such expressions for the shape parameters yield more reliable numerical values of the shape parameter than those obtained by least-mean-squares or polynomial fits. We show that the eigenphase representation is more meaningful than the ‘‘bar’’ phase shift representation and that the variation in the values of Pα in the models may be of significance.