The isoscalar $E2\mathrm{}$ giant resonance in ${}^{40}\mathrm{Ca}$ has been calculated within a microscopic approach which takes into account, in addition to the random-phase-approximation configurations, one-particle–one-hole (1p1h) $\otimes$phonon configurations and the continuum. We reproduce the observed shift of a considerable part of the $E2\mathrm{}$ strength to lower energies which gives rise to a nearly uniform distribution. If we add the $E0\mathrm{}$ strength calculated within the same approach, then we obtain good agreement with a recent electron scattering experiment, which is a further strong indication for low-lying $E0\mathrm{}$ strength.

• Received 7 July 1994

DOI:https://doi.org/10.1103/PhysRevLett.74.3943