Quantum Phase Crossover in the Spherical Mean-field plus Q·Q and Pairing Model within a Single-j Shell
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摘要: 介绍了单j壳的球形平均场加几何四极-四极和标准对力模型的量子相交叉行为。在单j=15/2的壳内,计算了随模型控制参数变化的多个物理量如低激发能级、激发态间重叠积分、低激发态间的B(E2)比值和电四极矩比值。结果显示,在类转动到对激发相的演化中,多个物理量在交叉区存在非常明显的变化,如B(E2;41 → 21)/B(E2;21 → 0g),B(E2;42 → 21)/B(E2;21 → 0g)等,并且这些变化在核子数达到半满壳时尤为显著。此外,尽管当j较小时,由几何四极-四极相互作用得到的低激发能级不满足转动谱规律,但当j值足够大时,这些低激发能级满足转动谱规律。
The analysis of the quantum phase crossover behavior in the spherical shell model mean-field plus the geometric quadrupole-quadrupole (Q·Q) and standard pairing model within a single-j shell is reported. Several quantities, such as low-lying excitation energies, the overlaps of excited states, ratios of some B(E2) and electric quadrupole moments of some low-lying states as functions of the control parameter of the model in a j=15/2 shell are calculated. The results show that there are noticeable changes in the crossover region of the rotational-like to the pair-excitation phase transition, such as B(E2;41 → 21)/B(E2;21 → 0g) and B(E2;42 → 21)/B(E2;21 → 0g), especially in the half-filling case. Though the low-lying excitation energies generated from the geometric quadrupole-quadrupole interaction not satisfy the pattern of a rotational spectrum when j is small, these energies follow the pattern of a rotational spectrum when j is sufficiently large.Abstract: The analysis of the quantum phase crossover behavior in the spherical shell model mean-field plus the geometric quadrupole-quadrupole (Q·Q) and standard pairing model within a single-j shell is reported. Several quantities, such as low-lying excitation energies, the overlaps of excited states, ratios of some B(E2) and electric quadrupole moments of some low-lying states as functions of the control parameter of the model in a j=15/2 shell are calculated. The results show that there are noticeable changes in the crossover region of the rotational-like to the pair-excitation phase transition, such as B(E2;41 → 21)/B(E2;21 → 0g) and B(E2;42 → 21)/B(E2;21 → 0g), especially in the half-filling case. Though the low-lying excitation energies generated from the geometric quadrupole-quadrupole interaction not satisfy the pattern of a rotational spectrum when j is small, these energies follow the pattern of a rotational spectrum when j is sufficiently large.-
Key words:
- shell model /
- quadrupole-quadrupole interaction /
- single-j shell
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[1] SACHDEV S. Quantum Phase Transitions[M]. Cambridge:Cambridge University, 1999. [2] HERTZ J A. Phys Rev B, 1976, 14:1165. [3] CAPRIO M A, CEJNAR P, IACHELLO F. Ann Phys (N. Y.), 2008, 323:1106. [4] BOHR A, MOTTELSON B R. Nuclear Structure vol I[M]. New York:Benjamin, 1969; BOHR A, MOTTELSON B R. Nuclear Structure Vol Ⅱ[M]. New York:Benjamin, 1975. [5] IACHELLO F, ARIMA A. The Interacting Boson Model[M]. Cambridge:Cambridge University, 1987. [6] CEJNAR P, JOLIE J. Prog Part Nucl Phys, 2009, 62:210. [7] CEJNAR P, JOLIE J, CASTEN R F. Rev Mod Phys, 2010, 82:2155. [8] IACHELLO F. Phys Rev Lett, 2000, 85:3580. [9] IACHELLO F. Phys Rev Lett, 2001, 87:052502. [10] BONATSOS D, LENIS D, PETRELLIS D, et al. Phys Lett B, 2004, 588:172. [11] ELLIOTT J P. Proc R Soc London Ser A, 1958, 245:128; ELLIOTT J P. Proc R Soc London Ser A, 1958, 245:562. [12] ELLIOTT J P, HARVEY M. Proc R Soc London Ser A, 1963, 272:557. [13] RING P, SCHUCK P. The Nuclear Many-Body Problem[M]. Berlin:Springer Verlag, 1980. [14] TALMI I. Simple Models of Complex Nuclei:The Shell Model and Interacting Boson Model[M]. Berlin:Springer, 1993. [15] ROWE D J, BAHRI C, WIJESUNDERA W. Phys Rev Lett, 1998, 80:4394. [16] BAHRI C, ROWE D J, WIJESUNDERA W. Phys Rev C, 1998, 58:1539. [17] LUO Y A, PAN F, WANG T, et al. Phys Rev C, 2006, 73:044323. [18] LUO Y A, ZHANG Y, MENG X F, et al. Phys Rev C, 2009, 80:014311. [19] LI B, PAN F, DRAAYER J P. Phys Rev C, 2016, 93:044312. [20] PAN F, LI B, ZHANG Y Z, et al. Phys Rev C, 2013, 88:034305. [21] PAN F, DRAAYER J P, LUO Y A. Phys Lett B, 2003, 576:297. [22] PAN F, ZHANG Y, DRAAYER J P. J Phys G, 2005, 31:1039. [23] ISACKER P V, HEINZE S. Ann Phys (N. Y.), 2014, 349:73. -
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