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Deng, J. K.; C., W.; Hamilton, J. H.; Ramayya, A. V.; Kormicki, J.; Gao, W.B.; Zhao, Xin; Shi, D.; Lee, I. Y.; Garrett, J.D.; Johnson, Noah R.; Winchell, D. F.; Halbert, M. L.; Baktash, C.

doi:10.1103/physrevc.52.595

Cited by 19 publications

(14 citation statements)

References 8 publications

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“…Instead, we propose it as a candidate for the predicted oblate K π = 16 + state with a two-proton-twoneutron configuration. [7,[12][13][14]46,48]. Our calculations reproduce well experimental values.…”

Section: Calculations and Discussionsupporting

confidence: 77%

“…In the classic picture, if the shape of an object keeps unchanged, the rotational spectrum should obey the regular I (I + 1) pattern. However, it was observed that in 184,186 Hg and 186 Pb, the oblate levels are compressed when compared to the regular I (I + 1) pattern [12][13][14]. Whether the origin of the irregular behavior involves significant shape change remains an open question [14].…”

Section: Calculations and Discussionmentioning

confidence: 99%

“…Although coexisting 0 + states in light Hg and Pb nuclei have been studied extensively [5,[8][9][10][11], the shape-changing effect remains unclear for high-spin states. Specifically, we seek to explain rotational bands based on oblate and prolate shapes, which have been observed in 184,186 Hg [12,13] and more recently in 186,188 Pb [7,14,15]. The shape coexistence or deformation change can be described by the total-Routhian-surface (TRS) calculation based on mean-field model [16,17].…”

Section: Introductionmentioning

confidence: 99%

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Shape-coexisting rotation in neutron-deficient Hg and Pb nuclei

et al. 2015

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For a shape-soft nucleus, the deformation change with increasing angular momentum of rotation can be significant. Total-Routhian-surface (TRS) calculations include the shape changes, but angular momentum is not conserved (neither is it a good quantum number, nor is it kept unchanged in the whole TRS mesh). In the projected shell model (PSM), the angular momentum appears as a good quantum number, but calculations have usually been performed with fixed deformation. In the present work, by performing angular-momentum projection on the mean-field potential-energy surface (PES), we can obtain an angular-momentum-conserved PES which gives deformation for a rotational state at a given spin. In order to investigate the shape-changing effect, we have chosen neutron-deficient Hg and Pb isotopes in which shape coexistence occurs. We interpret the irregular rotational behavior of the oblate bands at low spin as arising from deformation changes which are induced by collective rotation. At higher spin, the oblate rotational spectrum can also be influenced by the crossing between the K = 0 ground-state band and a low-K two-quasineutron band. Calculated g factors for the states of oblate bands are given for future experimental testing, and the intrinsic structures of high-K oblate states are investigated.

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Section: Calculations and Discussionsupporting

confidence: 77%

Section: Calculations and Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Shape-coexisting rotation in neutron-deficient Hg and Pb nuclei

et al. 2015

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“…[50], and probably 170 Er [51]. These three configurations have not been observed in the heavier isotones of N = 104 and 102, although similar band structure that might be associated with a K isomer has been observed in 184 Hg [52]. We note that the K π = 6 − ν{7/2 + [633], 5/2 − [512]} configuration has an unfavored residual spin-spin interaction (≈ +300 keV) while the residual interaction is favored for the 6 + , 7 − , and 8 − configurations (≈ −100 keV) [53].…”

Section: Calculations and Discussionmentioning

confidence: 86%

Multi-quasiparticle excitation: Extending shape coexistence inA~190neutron-deficient nuclei

et al. 2010

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Multi-quasiparticle high-K states in neutron-deficient mercury, lead, and polonium isotopes have been investigated systematically by means of configuration-constrained potential-energy-surfacecalculations. An abundance of high-K states is predicted with both prolate and oblate shapes, which extends the shape coexistence of the mass region. Well-deformed shapes provide good conditions for the formation of isomers, as exemplified in 188 Pb. Of particular interest is the prediction of low-lying 10 − states in polonium isotopes, which indicate long-lived isomers.

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“…The observed peak structure is attributed to the yrast-band transitions in 184 Hg (for a level scheme see Ref. [19]). The energy difference for transitions connecting low-lying yrast states is often similar to the binding-energy difference of 69 keV for electrons [20].…”

mentioning

confidence: 99%

Combined in-beam electron andγ-ray spectroscopy ofHg184,186

Scheck¹,

Butler²,

Gaffney³

et al. 2011

Phys. Rev. C

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By exploiting the SAGE spectrometer a simultaneous measurement of conversion electrons and γ rays emitted in the de-excitation of excited levels in the neutron-deficient nuclei 184,186 Hg was performed. The light Hg isotopes under investigation were produced using the 4n channels of the fusion-evaporation reactions of 40 Introduction. The neutron midshell Hg and Pb nuclei are some of the most interesting nuclei found in the nuclear landscape. In these nuclei evidence is found that indicates almost degenerate coexisting shapes at low excitation energies [1,2]. For 186 Pb, besides the 0 + ground state the first two excited states are 0 + states [3]. In the corresponding Hg isotopes, besides the ground-state band, a second band with a bandhead at low excitation energy is observed. Meanfield approaches produce different minima in the potential energy surface [4][5][6][7], leading to an identification of these structures as being deformed with one particular macroscopic nuclear shape. In the Pb isotopes these minima are found at deformation values corresponding to spherical, weakly oblate, and prolate shapes. In the light Hg isotopes two distinct minima are associated with weakly oblate and prolate deformation. Based on considerations of the moment of inertia it is proposed that ground-state and low-spin yrast states are members of the weakly oblate deformed band, while the first excited 0 + state is the bandhead of the well-deformed prolate band. In a simple intruder picture the underlying microscopic proton configurations are a π (0p-2h) two-hole structure (weakly oblate) and a π (2p-4h) two-particle-fourhole structure (prolate) [8], respectively. The bandhead energy of the intruding, prolate π (2p-4h) structure approaches the ground state given by the bandhead of the oblate π (0p-2h) band near neutron midshell at N = 104. Furthermore, the energy differences between the individual states of the two bands is lower for the prolate deformed band. Consequently, when approaching midshell the spin of the state for which the prolate band starts forming the yrast band lowers.The combined spectroscopic study of decay γ rays and electrons offers an opportunity to gain a more detailed picture of the interplay between the oblate and prolate bands. A

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New high-spin band structures inHg184

Cited by 19 publications

References 8 publications

Shape-coexisting rotation in neutron-deficient Hg and Pb nuclei

Shape-coexisting rotation in neutron-deficient Hg and Pb nuclei

Multi-quasiparticle excitation: Extending shape coexistence inA~190neutron-deficient nuclei

Combined in-beam electron andγ-ray spectroscopy ofHg184,186

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