Shape phase transition in odd-even nuclei: From spherical to deformedγ-unstable shapes

Abstract

Shape phase transitions in odd-A nuclei are investigated within the framework of the interacting boson-fermion model. The case of a single j = 9/2 fermion coupled to an even-even boson core is considered. This boson core transits from spherical to γ -unstable shapes depending on the value of a control parameter in the boson Hamiltonian. The effect of the coupling of the odd particle to this core along the shape transition and, in particular, at the critical point is discussed. For that purpose, the ground-state energy surface in terms of the β and γ shape variables for the even core and odd-even energy surfaces for the different K states coming from j = 9/2 are constructed. The evolution of each individual coupled state along the transition from the spherical [U(5)] to the γ -unstable [O(6)] situation is investigated. One finds that the core-fermion coupling gives rise to a smoother transition than in the even-core case.

Simple description of odd-Anuclei around the critical point of the spherical to axially deformed shape phase transition

“…This follows because the interaction between the core and the single-particle is expected to be quite strong in the odd-A nuclei when the core is well-deformed. In addition, a detailed comparison of the X(3/ 2j+1) model with the interacting boson-fermion model [42][43][44] and the SD-pair shell model [45,46] for odd-A nuclei would be interesting. Related work is in progress.…”

Shape phase transition and shape coexistence in the Bose-Fermi system

“…One can prove that the spherical to prolate SPTs may occur at η c = (1) is taken into account. Since a single-j shell is considered for the odd fermion, the pure fermion part contributes only an additional constant to the ground state energy [4].…”

“…Shape phase transitions (SPTs) in odd-even nuclei have received some attentions in recent years [1][2][3][4][5][6][7][8][9][10]. Evidences of the spherical to prolate SPT and the associated shape/phase coexistence have been clearly identified in the odd Sm nuclei [8].…”

“…A theoretical tool suitable for analyzing the SPTs in odd-even nuclei is the interacting boson-fermion model (IBFM) [11], in which odd-even nucleus is approximately considered as the Bose-Fermi system with an even-even core (boson) coupled to a single particle (fermion). Previous investigations reveal that the effects of single particle may influence different type of SPT in different way [4][5][6]. In this work, we will present a classical analysis of the effects of single particle on the spherical to prolate SPT within the framework of IBFM.…”

Algebraic solutions forUBF(5)−OBF(6)Jafarizadeh1, Ghapanvari2, Fouladi3 2015Phys. Rev. C220130View full textAdd to dashboardCite

“…Phase transitions is also investigate in odd-A nuclei within the framework of interacting boson -fermion model (IBF M ) [8], which describe nuclei in terms of correlated pairs, with L = 0, 2 (s , d bosons), and unpaired particles of angular momentum j (jf ermions).Studies of QP T s in odd-even nuclei were implicitly initiated years ago by Scholten and Blasi [9]. Several explicit studies have recently been made by Alonso et al [10][11][12] and by Boyukata et al [13], who also have suggested a simple form of the IBFM Hamiltonian, particularly well-suited to study QP T s in odd-even nuclei because of their supersymmetric properties. Similar to even-even nuclei, also exists critical point for odd-even and even-odd nuclei but in this case, critical points show with E(5/ j 2j + 1) and X(5/ j 2j + 1) that j is the angular momentum of single nucleon.…”