The higher Tamm-Dancoff Approximation (HTDA) is extended to include vibrational correlations with or without pairing correlations. The residual interaction in use is of the delta (in the $T=1$ channel) plus multipole-multipole type. In this paper we have limited our study to the mere case of isoscalar quadrupole correlations. The approach is illustrated by the consideration of ground state and isoscalar giant quadrupole resonance properties in the ${}^{40}\mathrm{Ca}$ nucleus.

• Received 30 January 2009

DOI:https://doi.org/10.1103/PhysRevC.81.044320