Blocking of coupling to the 02 + excitation in 154Gd by the [505]11/2- neutron in 155Gd

Sharpey‐Schafer, J. F.; Madiba, T. E.; Bvumbi, S. P.; Lawrie, E. A.; Lawrie, J. J.; Minkova, A.; Mullins, S. M.; Papka, P.; Roux, D. G.; Tímár, J.

doi:10.1140/epja/i2011-11006-7

Cited by 34 publications

(55 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Evidence indicating that the 0 2 + states in N = 88 and 90 nuclei are not β vibrations [6] but 2p-2h neutron states lowered into the pairing gap by configuration dependent pairing has been presented in Refs. [7,8]. It was argued that they are classic examples of "pairing isomers" [9] forming a "second vacuum" [7] on which a complete set of excited deformed states are built that are congruent to those built on the 0 1 + ground state.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Octupole correlations in the structure of02+bands in theN=88nuclei150
Bvumbi
¹
,
Sharpey‐Schafer
²
,
Jones
³

et al. 2013
Phys. Rev. C
Self Cite
27
1
8
0
View full text Add to dashboard Cite

Knowledge of the exact microscopic structure of the 0 1 + ground state and first excited 0 2 + state in 150 Sm is required to understand the branching of double β decay to these states from 150 Nd. The detailed spectroscopy of 150 Sm and 152 Gd has been studied using (α,xn) reactions and the γ -ray arrays AFRODITE and JUROGAM II. Consistently strong E1 transitions are observed between the excited K π = 0 2 + bands and the lowest negative parity bands in both nuclei. These results are discussed in terms of the possible permanent octupole deformation in the first excited K π = 0 2 + band and also in terms of the "tidal wave" model of Frauendorf.

show abstract

Section: Introductionmentioning

confidence: 99%

“…[7,8]. It was argued that they are classic examples of "pairing isomers" [9] forming a "second vacuum" [7] on which a complete set of excited deformed states are built that are congruent to those built on the 0 1 + ground state. Evidence for this [10] has also been found in 152 Sm.…”

Section: Introductionmentioning

confidence: 99%

Octupole correlations in the structure of02+bands in theN=88nuclei150
Bvumbi
¹
,
Sharpey‐Schafer
²
,
Jones
³

et al. 2013
Phys. Rev. C
Self Cite
27
1
8
0
View full text Add to dashboard Cite

show abstract

“…18 can be interpreted as due to K mixing within the parent states of the 162 Er, 164 Er, [24,[35][36][37][38][39][40]. The horizontal axis is the ratio of the ground-state-band dynamic and kinematic moments of inertia.…”

Section: B 162 Ermentioning

confidence: 99%

Discovery of isomers in dysprosium, holmium, and erbium isotopes withN=94to 97

et al. 2012

View full text Add to dashboard Cite

High-spin states in the 164 68 Er 96 region were studied using 9 Be + 160 Gd reactions. Pulsed beam conditions were exploited for enhanced sensitivity to delayed γ -ray transitions. New isomers were identified in 161 Dy, 163 Ho, 162 Er, and 165 Er. The 162 Er isomer is interpreted to decay by E1 transitions to the ground-state band with a reduced hindrance of f ν = 33. A plot of f ν values for all K = 7, E1 transitions from two-quasiparticle isomers to the ground-state bands of even-even nuclei reveals only a small influence from the dynamic to kinematic moment-of-inertia ratio, which provides a measure of Coriolis K mixing within the ground-state band. This is interpreted to imply that the relatively low hindrances are due to K mixing in the isomer, caused by a combination of Coriolis and octupole band mixing.

show abstract

“…This implies that |0 + 2 has a two-quasi-neutron configuration. In the following letter [53] it is shown that the odd neutron occupying the [505]11/2 − orbital in 155 Gd, blocks the coupling of this orbital to |0 + 2 . This determines the nature of the quasi-neutron configuration − orbital.…”

Section: (B)-(d)mentioning

confidence: 99%

Congruent band structures in 154Gd : Configuration-dependent pairing, a double vacuum and lack of $ \beta$ -vibrations

et al. 2011

Self Cite

View full text Add to dashboard Cite

Abstract. We have used the (α, 2n) and (α, 4n) reactions and the AFRODITE γ-ray spectrometer to make a comprehensive study of the nucleus 154 Gd below 20h. While the first excited 0 + 2 state at 681 keV is usually considered to be the head of a K π = 0 + β-vibrational band, we propose that the data are best described as two separate vacuum states, the ground state and the 681 keV level, each with its own γ and octupole vibrations, pairing and alignments. The implications of this finding, for understanding the structure of transitional rare-earth nuclei, are discussed.It has been a natural assumption since the early days of the collective model [1,2], that the first excited 0 + 2 state in deformed even-even nuclei is a β-vibration along the symmetry axis. Doubts about this assumption have been expressed [3][4][5][6][7][8][9][10][11][12] over the years and, more recently, a comprehensive review of the characteristic properties of such states was made by Garrett [13]. He found that the properties of most 0 + 2 states were not those of β-vibrations, e.g. in 166 Er [14], and he stressed the role pairing must play in the existence of the observed states.The rare-earth nuclei with neutron numbers N = 88 and 90 have particularly low-lying first excited 0 + 2 levels with excitation energies between 600 and 800 keV, well within the pairing gap of about 2.1 MeV. It has usually been assumed that these 0 + 2 levels are collective β-vibrations based on the ground state |0 + 1 vacuum in spite of the observation that they are very weakly excited in inelastic electron scattering [15,16], which is unusual for states with a collective nature. The N = 88 0 + 2 levels are strongly populated in (p,t) two-neutron pickup reactions [17][18][19][20][21] but are weakly populated in (t,p) two-neutron stripping reactions [22,23]. In contrast the N = 90 0 + 2 levels are weakly populated in the (p,t) reactions and strongly populated in the (t,p) reactions. If one assumes that the 0 + 2 levels correspond to collective β-vibrations it remains unclear why there would be a e-mail: jfss@tlabs.ac.za a substantial difference in the population patterns of these states. For nuclei with N ≥ 92 most of the two-neutron transfer strength is concentrated in the ground states [17][18][19][20][21][22]24], which is expected [25] for superfluid nuclei with a ground-state vacuum |0 + 1 well described by the BCS or Hartree-Fock-Bogolyubov theories [26].One should keep in mind that for the N = 88 and 90 nuclei even the most sophisticated models [2,4,27] fail to predict a β-vibration below about 1.5 MeV, adding further doubts about the interpretation of these states as β-vibrations. A totally different approach has been adopted by the Yale group [28] in which the 0 + 2 levels become s = 2 boson excitations [29][30][31] at a critical point X (5) symmetry.An alternative interpretation to β-vibrations for 0states was suggested for the actinide isotopes, where several 0 + 2 states that could not be described as a pairing or β-vibration had been observed by Maher et al...

show abstract

Blocking of coupling to the 02 + excitation in 154Gd by the [505]11/2- neutron in 155Gd

Cited by 34 publications

References 36 publications

Octupole correlations in the structure of02+bands in theN=88nuclei150
Bvumbi
¹
,
Sharpey‐Schafer
²
,
Jones
³

et al. 2013
Phys. Rev. C
Self Cite
27
1
8
0
View full text Add to dashboard Cite

Octupole correlations in the structure of02+bands in theN=88nuclei150
Bvumbi
¹
,
Sharpey‐Schafer
²
,
Jones
³

et al. 2013
Phys. Rev. C
Self Cite
27
1
8
0
View full text Add to dashboard Cite

Discovery of isomers in dysprosium, holmium, and erbium isotopes withN=94to 97

Congruent band structures in 154Gd : Configuration-dependent pairing, a double vacuum and lack of $ \beta$ -vibrations

Contact Info

Product

Resources

About

Blocking of coupling to the 02 + excitation in 154Gd by the [505]11/2- neutron in 155Gd

Cited by 34 publications

References 36 publications

Octupole correlations in the structure of02+bands in theN=88nuclei150Bvumbi1, Sharpey‐Schafer2, Jones3 et al. 2013Phys. Rev. CSelf Cite27180View full textAdd to dashboardCite

Octupole correlations in the structure of02+bands in theN=88nuclei150Bvumbi1, Sharpey‐Schafer2, Jones3 et al. 2013Phys. Rev. CSelf Cite27180View full textAdd to dashboardCite

Discovery of isomers in dysprosium, holmium, and erbium isotopes withN=94to 97

Congruent band structures in 154Gd : Configuration-dependent pairing, a double vacuum and lack of $ \beta$ -vibrations

Contact Info

Product

Resources

About

Octupole correlations in the structure of02+bands in theN=88nuclei150
Bvumbi
¹
,
Sharpey‐Schafer
²
,
Jones
³

et al. 2013
Phys. Rev. C
Self Cite
27
1
8
0
View full text Add to dashboard Cite

Octupole correlations in the structure of02+bands in theN=88nuclei150
Bvumbi
¹
,
Sharpey‐Schafer
²
,
Jones
³

et al. 2013
Phys. Rev. C
Self Cite
27
1
8
0
View full text Add to dashboard Cite