Investigation of collectivity in the neutron-rich 142Xe

Abstract

The neutron-rich 142Xe lies north-east of the doubly-magic 132Sn, in a region that is not only describable by nuclear theory with single-particle and mean-field approaches, but also became accessible in experiments in recent times. Since the astrophysical r process passes through the area, understanding the structure of nuclei therein may provide insight into the A=130 peak in the solar-element abundances. Furthermore, 144Ba, a nucleus that exhibits strong octupole collectivity, lies in the immediate proximity just two protons above 142Xe. In order to gain understanding on the evolution of quadrupole and octupole collectivity in this region, a Coulomb excitation experiment was carried out using the MINIBALL and C-REX setup at the HIE-ISOLDE facility, CERN. Several reduced transition strengths of low-lying transitions along with the spectroscopic quadrupole moments of the respective states could be determined. Additionally, new low-spin low-energy states, interpreted as part of a gamma band, demonstrated for the first time in this isotope, could be identified, and the location of the 3- state supported. The results are compared to SCCM and LSSM calculations.