Backbending: Coriolis antipairing or rotational alignment?

Faessler, Amand; Devi, K. R. Sandhya; Grümmer, F.; Schmid, K.W.; Hilton, R.R.

doi:10.1016/0375-9474(76)90097-x

Cited by 163 publications

(19 citation statements)

References 22 publications

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“…From this simple model the gap decreases monotonically to zero at a critical temperature of T c ∼ 0.5 ∆. However, if particle number is projected out [27,28], the decrease is significantly delayed. The predicted decrease of pair correlations takes place over several MeV of excitation energy [28].…”

Section: Thermodynamic Properties Of Nuclei and Pairingmentioning

confidence: 97%

Pairing correlations and transitions in nuclear systems

Belić¹,

Dean²,

Hjorth‐Jensen³

2004

Nuclear Physics A

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We discuss several pairing-related phenomena in nuclear systems, ranging from superfluidity in neutron stars to the gradual breaking of pairs in finite nuclei. We describe recent experimental evidence that points to a relation between pairing and phase transitions (or transformations) in finite nuclear systems. A simple pairing interaction model is used in order to study and classify an eventual pairing phase transition in finite fermionic systems such as nuclei. We show that systems with as few as ∼ 10−16 fermions can exhibit clear features reminiscent of a phase transition.

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Section: Thermodynamic Properties Of Nuclei and Pairingmentioning

confidence: 97%

Pairing correlations and transitions in nuclear systems

Belić¹,

Dean²,

Hjorth‐Jensen³

2004

Nuclear Physics A

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“…In high spin physics, the backbending phenomenon is a beautiful manifestation of the breaking of pairs. The mechanism is induced by Coriolis forces tending to align single particle angular momenta along the nuclear rotational axis [3,4]. Theoretical models also predict reduction in the pair correlations at higher temperatures [5][6][7].…”

Section: Introductionmentioning

confidence: 99%

“…In Sect. 4 we present the experimental findings and relate them to the simple pairing model of Sect. 3.…”

Section: Introductionmentioning

confidence: 99%

Entropy in hot161,162Dyand171
Guttormsen
¹
,
Bjerve
²
,
Hjorth‐Jensen
³

et al. 2000
Phys. Rev. C
38
6
40
0
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The density of accessible levels at low spin in the ( 3 He,αγ) reaction has been extracted for the 161,162 Dy and 171,172 Yb nuclei. The entropy of the even-odd and even-even nuclei has been deduced as a function of excitation energy, and found to reach a maximum of 15 kB before neutron evaporation. The entropy of one quasi-particle outside an even-even core is found to be 1.70 (15) kB. This quasi-particle picture of hot nuclei is well accounted for within a simple pairing model. The onset of two, four and six quasi-particle excitations in the 162 Dy and 172 Yb nuclei is discussed and compared to theory. The number of quasi-particles excited per excitation energy is a measure for the ratio of the level energy spacing and the pairing strength. PACS number(s): 21.10. Ma, 24.10.Pa, 25.55.Hp, 27.70.+q

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“…The normalization factor of this state is defined by the matrix element 21) which is determined in a similar way as the norm of the projected BCS function (see Appendix B). The upper limit of the J f is still 24 even after the application of the quasiparticle creation operators, because it is the maximum angular momentum which can be realized in the i 13/2 intruder orbital, irrespective of the number of particles involved.…”

Section: B Spherical Projected States From a Deformed Bcs Statementioning

confidence: 99%

Semimicroscopic description of backbending phenomena in some deformed even-even nuclei

Râduţâ¹,

Budaca²

2011

Phys. Rev. C

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The mechanism of backbending is semi-phenomenologically investigated based on the hybridization of two rotational bands. These bands are defined by treating a model Hamiltonian describing two interacting subsystems: a set of particles moving in a deformed mean-field and interacting among themselves through an effective pairing force and a phenomenological deformed core whose intrinsic ground state is an axially symmetric coherent boson state. The two components interact with each other by a quadrupole-quadrupole and a spin-spin interaction. The total Hamiltonian is considered in the space of states with good angular momentum, projected from a quadrupole deformed product function. The single-particle factor function defines the nature of the rotational bands, one corresponding to the ground band in which all particles are paired and another one built upon a i 13/2 neutron broken pair. The formalism is applied to six deformed even-even nuclei, known as being good backbenders. Agreement between theory and experiment is fairly good.

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Backbending: Coriolis antipairing or rotational alignment?

Cited by 163 publications

References 22 publications

Pairing correlations and transitions in nuclear systems

Pairing correlations and transitions in nuclear systems

Entropy in hot161,162Dyand171
Guttormsen
¹
,
Bjerve
²
,
Hjorth‐Jensen
³

et al. 2000
Phys. Rev. C
38
6
40
0
View full text Add to dashboard Cite

Semimicroscopic description of backbending phenomena in some deformed even-even nuclei

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Backbending: Coriolis antipairing or rotational alignment?

Cited by 163 publications

References 22 publications

Pairing correlations and transitions in nuclear systems

Pairing correlations and transitions in nuclear systems

Entropy in hot161,162Dyand171Guttormsen1, Bjerve2, Hjorth‐Jensen3 et al. 2000Phys. Rev. C386400View full textAdd to dashboardCite

Semimicroscopic description of backbending phenomena in some deformed even-even nuclei

Contact Info

Product

Resources

About

Entropy in hot161,162Dyand171
Guttormsen
¹
,
Bjerve
²
,
Hjorth‐Jensen
³

et al. 2000
Phys. Rev. C
38
6
40
0
View full text Add to dashboard Cite