The Isovector Quadrupole-Quadrupole Interaction Used in Shell Model Calculations with $\Delta N=2$ Excitations

Abstract

The effect of the ``$B$'' term in the interaction $-\chi Q\cdot Q(1+B\vec{\tau }(1)\cdot \vec{\tau }(2))$, which was previously considered in the $0p$ shell, is now studied in a larger space which includes $\Delta N=2$ excitations. We still get a collapse of low-lying states below the conventional $J=0^{+}$ ground state when $B$ is made sufficiently negative.

13 pages, revtex, (submitted to Phys. Rev. C). Four figures available on request from [email protected]