Proton particle-hole states and collective excitations in 196Pb

Penninga, J.; Hesselink, W.H.A.; Bałanda, A.; Stolk, Arian; Verheul, H.; Vanklinken, J; Riezebos, H.J.; Devoigt, Mja

doi:10.1016/0375-9474(87)90098-4

Cited by 67 publications

(12 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…3(b)] is of key importance for our calculations. In this isotope, an even-spin side band exhibiting the characteristics of a collective band has been measured and is understood as a 2p-2h intruder band [10,31,35]. Similar to the previously discussed isotopes, Band I is a mainly 2p-2h band and Band II is a mainly 4p-4h band.…”

Section: Resultsmentioning

confidence: 58%

Configuration mixing in the neutron-deficientPb186−196isotopes

2008

View full text Add to dashboard Cite

In this article we report the results of detailed interacting boson model calculations with configuration mixing for the neutron-deficient Pb isotopes. Calculated energy levels and B(E2) values for 188−196 Pb are discussed and some care is suggested concerning the current classification on the basis of level systematics of the 4 + 1 and 6 + 1 states in 190−194 Pb. Furthermore, quadrupole deformations are extracted for 186−196 Pb and the mixing between the different families (0p-0h, 2p-2h, and 4p-4h) is discussed in detail. Finally, the experimental and the theoretical level systematics are compared.

show abstract

Section: Resultsmentioning

confidence: 58%

Configuration mixing in the neutron-deficientPb186−196isotopes

2008

View full text Add to dashboard Cite

show abstract

“…Clear evidence for the coexistence at low energies and low angular momenta of spherical, oblate and prolate shapes has been observed in Pb isotopes with 104 ≤ N ≤ 108 [6][7][8][9]. In the region with 110 ≤ N ≤ 116, the low-lying states are dominated by spherical and oblate configurations [10][11][12][13]. The systematic changes in the relative energies and depths of these minima with decreasing neutron number provide a sensitive test of nuclear models.…”

Section: Introductionmentioning

confidence: 99%

On the character of three 8+ states in 192Pb

et al. 2010

View full text Add to dashboard Cite

Three low-lying 8 + states have been identified in 192 Pb. A newly observed cascade of γ-rays built directly on the 8 + 1 state is compared to the previously identified, weakly rotational band above the 11 − πi 13/2 , h 9/2 isomer in the same nucleus, and to analogous structures in 194 Pb. The similarity of all four structures lends support to the suggestion that the 8 + 1 configurations are of a similar oblate deformation to the 11 − isomers. The excitation energies of all three 8 + states in 192 Pb and 190 Pb are compared to systematics. The possibility that one of the 8 + states in 192 Pb is associated with a prolate shape is discounted.

show abstract

“…They are not known in heavier Pb, most probably because they are not yrast. These states are interpreted as a two-quasiparticle (2qp) excitation based on the π(h 9/2 i 13/2 ) K π =11 − single-particle configuration as confirmed in 196 Pb by the measurement of its g-factor [14]. Experimental information on deformation is extracted from the collective bands based on the excited 0 + [5, 7, 14, 15] and 11 − states [16,17].…”

mentioning

confidence: 96%

Self-consistent approach to deformation of intruder states in neutron-deficient Pb and Po

2003

View full text Add to dashboard Cite

We present systematic calculations of the properties of 11 − isomers in neutron-deficient [184][185][186][187][188][189][190][191][192][193][194][195][196][197][198] Po. These states are based on the π(h 9/2 i 13/2 ) K π =11 − configuration. They are calculated in the framework of the Hartree-Fock-Bogoliubov method with a Skyrme interaction and densitydependent pairing force. The energies and deformations of the 11 − states are compared to those of the intruder 0 + states in both Pb and Po isotopes. In the most neutron-deficient Po isotopes, the calculations predict, below a weakly oblate 11 − state, another oblate 11 − state which is even more deformed than the intruder oblate 11 − state in their Pb isotones. The energies and quadrupole moments of the 11 − isomers, corresponding to a weakly oblate nuclear shape, are in fair agreement with the available experimental data.The neutron-deficient nuclei around the Z = 82 shell closure constitute one of the most famous examples of shape coexistence [1,2]. In Pb isotopes, oblate, prolate and superdeformed configurations coexisting with a spherical ground state were predicted theoretically (see [3] and references therein) and identified experimentally [2, 4] more than ten years ago. By now, low-lying 0 + states, which are a characteristic feature of shape coexistence, are known from 202 Pb down to 184 Pb [5,6,7,8]. The interpretation of these low-lying 0 + states relies on proton excitations across the Z = 82 spherical shell gap. In a shell model picture [9,10], the energy of these multi-particle-multi-hole (mp-mh) configurations is lowered by the quadrupole-quadrupole and pairing interactions. In mean-field models [11,12], these structures are described by a state with an oblate (prolate) quadrupole deformation, whose low energy is due to the occupation of deformed intruder orbits, such as the down-sloping πh 9/2 -orbital for an oblate state.High-spin isomers constructed on these 0 + states are of particular interest since the measurement of their static electromagnetic moments provides direct information on both their single-particle structure and their deformation. Several isomeric states are known in Pb isotopes. In particular, 11 − levels have been observed from 188 Pb to 198 Pb (see, e.g. Ref.[13]). They are not known in heavier Pb, most probably because they are not yrast. These states are interpreted as a two-quasiparticle (2qp) excitation based on the π(h 9/2 i 13/2 ) K π =11 − single-particle configuration as confirmed in 196 Pb by the measurement of its g-factor [14]. Experimental information on deformation is extracted from the collective bands based on the excited 0 + [5, 7, 14, 15] and 11 − states [16,17]. Recent data on static quadrupole moments for 11 − states in 194,196 Pb [18,19] support the mean-field interpretation of these states as weakly deformed oblate configurations.The experimental excitation energies of the 11 − states and of the 0 + 2 states in Pb isotopes are shown in the left part of Fig. 1. Both exhibit a similar behavior. The steady decre...

show abstract

Proton particle-hole states and collective excitations in 196Pb

Cited by 67 publications

References 8 publications

Configuration mixing in the neutron-deficientPb186−196isotopes

Configuration mixing in the neutron-deficientPb186−196isotopes

On the character of three 8+ states in 192Pb

Self-consistent approach to deformation of intruder states in neutron-deficient Pb and Po

Contact Info

Product

Resources

About