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The spectroscopic quadrupole moments of the 11(-) and 12(+) isomers in Pb-192,Pb-194, described by the 3s(1/2)(-2)1h(9/2)1i(13/2) intruder two-proton and 1i(13/2)(2) two-quasi neutron configurations, respectively, have been determined by the method of time-differential observation of the gamma-ray perturbed angular distribution. The derived values are vertical bar Q(s)vertical bar(12(+),Pb-192) = 0.32(4) eb, vertical bar Q(s)vertical bar(11(-),Pb-192) = 2.9(3) eb and vertical bar Q(s)vertical bar(11(-),Pb-194) = 3.6(4) eb. The 8(+) 2304 keV and 9(-) 2514 keV states in Pb-192 have been identified as isomers, with half-lives of 3.9(3) and 3.3(2) ns, respectively. The experimental spectroscopic quadrupole moments for the 11(-) and 12(+) isomers in neutron deficient Pb nuclei have been described in the framework of the pairing plus quadrupole model. The intrinsic quadrupole moments and deformation of the 11(-) isomers are compared with the predictions of mean-field and interacting boson models. (C) 2007 Elsevier B.V. All rights reserved. ispartof: Physics Letters B vol:650 issue:2 pages:141-147 status: published

Background: The Po, Pb, Hg, and Pt region is known for the presence of coexisting structures that correspond to different particle-hole configurations in the Shell Model language or equivalently to nuclear shapes with different deformation. Purpose: We intend to study the configuration mixing phenomenon in the Hg isotopes and to understand how different observables are influenced by it. Method: We study in detail a long chain of mercury isotopes, $^{172-200}$Hg, using the interacting boson model with configuration mixing. The parameters of the Hamiltonians are fixed through a least square fit to the known energies and absolute B(E2) transition rates of states up to $3$ MeV. Results: We obtained the IBM-CM Hamiltonians and we calculate excitation energies, B(E2)'s, quadrupole shape invariants, wave functions, isotopic shifts, and mean field energy surfaces. Conclusions: We obtain a fairly good agreement with the experimental data for all the studied observables and we conclude that the Hamiltonian and the states we obtain constitute a good approximation to the Hg isotopes., We are very grateful to K. Wrzosek-Lipska, E. Rapisarda, and L. Gaffney for generous sharing of theirmost recent results on Coulomb excitation (A = 182-188), beta-decay results for A = 182 and A = 184 and new lifetime data for A = 184 and A = 186. We thank M. Huyse and P. Van Duppen for continuous interest in this research topic and J. L. Wood for stimulating discussions in various stages of this work and his diligence to quote from his unpublished notes. Financial support from the "FWO-Vlaanderen" (K.H. and J.E.G.R.) and the InterUniversity Attraction Poles Programme, Belgian State, Federal Office for Scientific, Technical and Cultural Affairs (IAP Grant No. P7/12) is acknowledged. This work has also been partially supported by the Spanish Ministerio de Economia y Competitividad and the European regional development fund (FEDER) under Project No. FIS2011-28738-C02-02, by Junta de Andalucia under Project No. FQM318, and P07-FQM-02962, and by Spanish Consolider-Ingenio 2010 (CPANCSD2007-00042).