Investigation of nuclear structure by resonance fluorescence scattering

Abstract

After and introduction to the subject, the formalism describing nuclear resonance scattering (NRF) is briefly summarized. Experimental techniques and developments are discussed in some detail. Recent results are presented from systematic NRF experiments studying low-lying dipole excitations in heavy nuclei. The following topics are covered: the systematics and fragmentation of the M1 Scissors Mode in even-even rare earth and actinide nuclei, its deformation dependence and saturation behaviour, the existence of the Scissors Mode in odd deformed nuclei, 2+⊗ 3− two-phonon E1 excitations in N=82 isotones and Z=50 isotopes, 2+⊗ 3− ⊗ particle multiplets in odd nuclei around N=82, low-lying ΔK=0 electric dipole excitations in deformed nuclei, and E1 excitations around 2.6 MeV in deformed nuclei, which are interpreted as candidates for novel two-phonon excitations (coupling of the K=1 octupole and K=2 γ-vibrations).