Evidence for radiative coupling of the pygmy dipole resonance to excited states

Abstract

The photoabsorption cross section and ground-state branching ratio of Nd-142 were measured using quasimonoenergetic gamma-ray beams at several beam energies. Two peaks corresponding to the pygmy dipole resonance (PDR) were identified.

The branching ratios were compared to statistical-model calculations. We found that the Brink hypothesis is violated, and that the branching ratios are only reproduced by introducing a possible new decay mode of the observed PDR.

Keywords

• strength function
• giant-resonances
• cross-sections
• n=82 nuclei
• scattering
• width
• zr