The isoscalar giant monopole, dipole, and quadrupole strength distributions
have been deduced in 90,92Zr, and 92Mo from "background-free"
spectra of inelastic α-particle scattering at a beam energy of 385 MeV
at extremely forward angles, including 0∘. These strength
distributions were extracted by a multipole-decomposition analysis based on the
expected angular distributions of the respective multipoles. All these strength
distributions for the three nuclei practically coincide with each other,
affirming that giant resonances, being collective phenomena, are not influenced
by nuclear shell structure near A∼90, contrary to the claim in a recent
measurement.Comment: 12 pages, 12 figures; Accepted for publication in Phys. Rev. C. arXiv
admin note: text overlap with arXiv:1607.0219