Shape coexistence in the neutron-deficient lead region: A systematic study of lifetimes in the even-even $^{188-200}$Hg with GRIFFIN

Abstract

Lifetimes of 2 +1 and 4 + 1 states, as well as some negative-parity and non-yrast states, in 188−200 Hg were measured using γ − γ electronic fast timing techniques with the LaBr3(Ce) detector array of the GRIFFIN spectrometer. The excited states were populated in the /β + -decay of J π = 7 + /2 − 188−200 Tl produced at the TRIUMF-ISAC facility. The deduced B(E2) values are compared to different interacting boson model predictions. The precision achieved in this work over previous ones allows for a meaningful comparison with the different theoretical models of these transitional Hg isotopes, which confirms the onset of state mixing in 190 Hg.