Wave functions of the Q.Q interaction in terms of unitary 9-j coefficients

Abstract

We obtain wave functions for 2 protons and 2 neutrons in the g_{9/2} shell expressed as column vectors with amplitudes D(J_{p},J_{n}). When we use a quadrupole-quadrupole interaction (Q.Q) we get, in many cases, a very strong overlap with wave functions given by a single set of unitary 9j coefficients --U9j= ((jj)^{2j} (jj^{J_{B}} \ (jj)^{J_{p}} (jj)^{J_{n}})^{I}. Here J_{B}=9 for even I T =0 states. For both even and odd T=1 states we take JB equal to 8 whilst for odd I, T=0 we take JB to be 7. We compare the Q.Q results with those of a more realistic interaction.