Unique and complementary information on shape coexistence in the neutron-deficient Pb region derived from Coulomb excitation

Neutron-deficient isotopes of Pt–Hg–Pb–Po–Rn are the classic region in the investigation of shape coexistence in atomic nuclei. A large programme of Coulomb-excitation experiments has been undertaken at the REX-ISOLDE facility in CERN with a number of even–even isotopes in this region. These experiments have been used to probe the electromagnetic properties of yrast and non-yrast states of even–even exotic nuclei, above and below Z = 82. Amongst a large amount of different complementary techniques used to study nuclear structure, Coulomb excitation brings substantial and unique information detailing shape coexistence. In this paper we review the Coulomb-excitation campaign at REX-ISOLDE in the light-lead region together with most recently obtained results. Furthermore, we present some new interpretations that arise from this data and show testing comparisons to state-of-the-art nuclear models.