Collective states of ^{3}He clusters

The monopole (L=0) and quadrupole (L=2) strength distributions in normal ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ clusters are calculated within the random-phase approximation. We use a phenomenological, zero-range ${}_{}{}^3{}_{}{}^{}\mathrm{-}_{}^3{}_{}{}^{}$He interaction to generate the Hartree-Fock single-particle spectrum and the residual particle-hole interaction. The evolution of the collective modes with the number of atoms in the cluster is discussed.