New giant resonances found near giant dipole resonance

For years a familiar feature of the nuclear spectrum has been the giant dipole resonance (GDR) located at $(70–80)/A1/3 MeV$ with a width of several MeV. Recently nuclear physicists have been excited to find other giant resonances at neighboring or higher energies. The interesting feature of the discovery of this new multipole excitation is not so much its actual occurrence, for that was expected theoretically, but that its strength is concentrated in a sufficiently narrow energy range for it to form a giant resonance that can be detected experimentally. The most prominent of these new resonances appears to be an isoscalar quadrupole resonance located just a few MeV below the giant dipole and having a comparable width.