Lifetimes and moments measurements to investigate the structure of midheavy nuclei

Abstract

Mid-heavy nuclei offer unique opportunities to study the collective and single-particle aspects of nuclear structure. This mass regime is a dynamic area where protons and neutrons generally occupy different orbitals, giving rise to complex structures with a wide variety of shapes, shape evolution and shape coexistence. To that end, measurements of nuclear lifetimes and electromagnetic moments ($\mu$,$Q$) can be invaluable. Recent experimental activities of the NuSTRAP group in Athens have focused on $\gamma$-spectroscopy studies employing the RoSPHERE array in Magurele, Romania. In recent studies [1,2], the neutron-rich ${}^{144-146}$Ba isotopes have exhibited octupole degrees of freedom. Similar questions exist for the lighter ${}^{140}$Ba isotope, which is located at the onset of octupole collectivity. In addition, understanding the structure of heavier, even-even hafnium isotopes requires more data regarding shape coexistence and shape evolution. Preliminary results on lifetimes in this area pave the way to understand dynamical phenomena prior to studying more exotic species in the future.

Comments: 7 pages, 4 figures, peer-reviewed paper accepted for publication in Bulg. J. Phys. after it was presented at International Workshop "Shapes and Dynamics of Atomic Nuclei: Contemporary Aspects" (SDANCA-19), 3-5 October 2019, Sofia, Bulgaria