[en] The two very neutron-deficient isotopes of lead A=190, 192 have been produced and studied through the reaction ¹⁵⁶Gd-¹⁵⁴Gd(⁴⁰Ar,4nγ)¹⁹²Pb-¹⁹⁰Pb. The identification of those nuclei was also studied by means of the two additional reactions: ¹⁸²W(¹⁶O,6nγ)¹⁹²Pb and ¹⁵⁶Gd(⁴⁰Ar,6nγ)¹⁹⁰Pb. The pulsed ⁴⁰Ar beam available at ALICE (Orsay) enabled to record single γ spectra as well as four dimensional (energy-time) spectra corresponding to the correlation of two Ge(Li) detectors for different time windows. Tentative level-schemes are proposed. No significant deviation from the behavior previously reported for the heavier isotopes (ref.1) is pointed out. The data are consistently reproduced within a 2 q.p formalism using an S.D.I. residual interaction. However a slow decrease of the 2₁⁺ level energy is observed which could be an indication of a weakly increasing collective trend when the number of neutron holes increases. Those experimental conclusions fairly agree with the theoretical predictions by F.Dickman and K.Dietrich (ref.2). As a matter of fact, the authors predict a spherical shape for the ground states and find a secondary prolate minimum of the deformation potential at low energy. But the latter is not well developped for A>184 suggesting a spherical behavior for the heavier isotopes

[en] The Relatvistic Hartree-Bogoliubov (RHB) theory is used to explore the structure of superdeformed (SD) ^190,212Pb isotopes using the non-linear NL3* and density dependent (DD-ME2, DD-PC1) interactions. We have studied the the excitation energy, the potential depth and the deformation of these Pb isotopes

[en] Calculations are presented for low-lying 0⁺ excited states in the neutron deficient Pb isotopes ^182-190Pb using both the HFB method with a Gogny interaction and a many-body method with phenomenological interaction strengths. The calculations suggest the presence of an as yet unobserved oblate 0⁺

No abstract available

[en] The current experimental search for neutron deficient Pb region has given new imminent into the low lying excitation of atomic nuclei. Spectacular instances of shape coexistence nearby the Z=82 shell closure are observed in even-even nuclei and there is a little existing knowledge concerning shape coexistence and intruder states with Z≥ 82

[en] The characteristics of shell model magic number of Z =3D 82 are reviewed in neutron-deficient nuclei. The reduced α width of ^188,190Pb are reported and the magic number of Z =3D 82 is confirmed

[en] The absolute α-decay width of light lead isotopes is calculated within a spherical BCS formalism. Clustering features induced by the nuclear interaction appear by considering a large configuration space. Good agreement with experimental data is obtained

[en] The α-decay rates of ¹⁸⁶,¹⁸⁸,¹⁹⁰,¹⁹²Pb have been reported to have an anomalous dependence on neutron number. Theoretical calculations do not reproduce this unusual behavior. To obtain more precise α-decay branching ratios, we reinvestigated the decay properties of ¹⁸⁸,¹⁹⁰,¹⁹²Pb. Our data result in α-decay reduced widths whose dependence on N is similar to that observed for other elements. (orig.)

[en] The projected shell model is applied to the nuclei ¹⁸⁶Pb, ¹⁸⁸Pb and ¹⁹⁰Pb. The low-lying prolate bands of them are calculated and the results are compared with experimental data, the low-lying band heads of these three nuclei are predicted, the reliability of this prediction is validated when the authors apply this model to the nucleus ¹⁸⁶Hg and it gives a satisfactory agreement with the experimental data

[en] Axial and triaxial calculations within RHB have been done to study the shape coexistence phenomena in the lead isotopes. Triplet states have been found in the^184-190Pb which are in accordance with the experimental and other theoretical observations. The energy difference (in MeV) between the first two excited states also gives the evidence for the same