-0.8 -0.7 -0.6 -0.5 -0.4 -0.3 tan 2nd 0 0.2 0.4 0.6 0.8 1  [fm$^{-1}$] -12 -11 -10 -9 -8 I [fm -3/2 ] M=20 M=30 M=40 M=20 M=30 M=40 FIG. 2: The two-nucleon second order estimate  [tan δ$_{1}$ ] 2 $^{nd}$  calculated using Ψ$_{1}$ as a function of the non linear parameter γ   for the values M = 20   30   40 and the integral I$_{γ}$ as a function of γ at the same three values of M . 29