Central depression in the charge distributions of He3 and He4

Recently Ballot and Fabre de la Ripelle pointed out that the central depression in the "empirical" point proton distribution of He3 could be attributed to the two-pion-exchange three-body force. We examine this mechanism by constructing simple phenomenological wave functions of the form of f(x)f(y)f(z)[1-Σg(x)g(y)(3 cos2θz-1)]n, where x, y, and z are the interparticle distances, cosθz=x→·y→xy, n=12 or 1, and Σ implies the cyclic summation over …