Speaker
Description
The structure of the $^{68}$Zn isotope is investigated using nuclear resonance fluorescence, where low-spin levels were excited using linearly polarized photon beams at energies ranging from 3 MeV to the particle threshold using the High Intensity Gamma-Ray Source. This nucleus is the isotone of $^{66}$Ni where triple shape coexistence has been established recently.
Excited states of interest were cataloged across a broad range of energies. The resulting gamma decay was measured and characterized using an array of high-purity germanium clover detectors and cerium bromide scintillators. Two 40-hour coincidence measurements were performed at beam energies just below the particle threshold to investigate low-lying, low-spin excited states, which are fed by the decay cascades of high-energy states populated directly by the beam. The low-spin gamma-decay data will be used to investigate the structure of $^{68}$Zn in the shell-model picture, comparing the observables, i.e., spin and parity quantum numbers, excitation energies, branching ratios, multipole mixing ratios, and scattering cross section data to the results of calculations using different effective shell-model interactions.
This research is supported in part by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Grants No. DE-FG02-97ER41041 (UNC), No. DE-FG02-97ER41033 (TUNL).
