Collectivity and configuration mixing in 186,188Pb and 194Po

Lifetimes of prolate intruder states in 186Pb and oblate intruder states in 194Po have been determined by employing, for the first time, the recoil-decay tagging technique in recoil distance Doppler-shift lifetime measurements. In addition, lifetime measurements of prolate states in 188Pb up to the 8+ state were carried out using the recoil-gating method. The B(E2) values have been deduced from which deformation parameters |β2|=0.29(5) and |β2|=0.17(3) for the prolate and the oblate bands, respectively, have been extracted. The results also shed new light on the mixing between different shapes

Study of the Ba-131 nucleus with the ((d)over-right-arrow, t) reaction

Excited states in Ba-131 were studied with the Ba-132((d) over right arrow, t) Ba-131 reaction at 24.0 MeV, with polarized deuteron beam using the Munich magnetic spectrograph Q3D. Unambiguous spin-parity assignments were made for many levels up to an excitation energy of 2.2 MeV. A detailed comparison is made between the experimental level scheme and interacting boson-fermion model calculations

Study of the (133)Ba nucleus with the ((d)over-right-arrow, p) reaction

Excited states in (133)Ba were studied with the (132)Ba((d) over right arrow, p)(133)Ba reaction at 24.0MeV, with a polarized deuteron beam using the Munich magnetic spectrograph Q3D. Many unambiguous spin-parity assignments were made up to an excitation energy of 2.2MeV, which allow a detailed comparison with different theoretical calculations, such as the interacting boson-fermion model and the shell model

Study of the Ba-130 nucleus with the (p, t) reaction

Excited states in Ba-130 have been studied with the 25MeV Ba-132(p, t) Ba-130 reaction with 8 keV energy resolution, at the Munich Q3D spectrograph. 27 excited states were observed up to 2.6MeV excitation energy, for 21 of them spin and parity being confirmed or assigned. These results complement earlier measurements concerning the systematics of 0(+) states in Ba-132 and Ba-134, and allow a more detailed comparison with predictions of different nuclear-structure models. The comparison with interacting boson model calculations brings additional evidence in favor of a description of this nucleus by parameters close to the O(6) symmetry

Collectivity in neutron-deficient Pb and Po nuclei

Lifetimes of low-lying yrast states in186Pb and194Po have been determined by employing, for the first time, the recoil-decay tagging technique in recoil distance Doppler-shift lifetime measurements. In addition, lifetime measurements of prolate states in188Pb up to the 8+ state were carried out using the recoil gating method. The deformation parameters β2 = 0.29(5) and β2 for the prolate (186,188Pb) and the oblate (194Po) bands, respectively, have been extracted from the measured lifetimes