The algebraic framework of the interacting boson model with configuration mixing is employed to demonstrate the occurrence of intertwined quantum phase transitions (IQPTs) in the $_{40}$Zr isotopes with neutron number 52-70. The detailed quantum and classical analyses reveal a QPT of crossing normal and intruder configurations superimposed on a QPT of the intruder configuration from U(5) to SU(3) and a crossover from SU(3) to SO(6) dynamical symmetries.
We explore the situation of intertwined quantum phase transitions (IQPTs), for which a QPT involving a crossing of two configurations is accompanied by a shape evolution of each configuration with its own separate QPT. We demonstrate the relevance of IQPTs to the Zr isotopes, with such coexisting Type I and Type II QPTs, and ground state shapes changing from spherical to prolate axially deformed and finally to gamma-unstable. Evidence for this scenario is provided by a detailed comparison with experimental data, using a definite symmetry-based conceptual framework.
The zirconium isotopes with $A=$ 92$-$110 have one of the most complicated evolution of structure in the nuclear chart. In order to understand the structural evolution of these isotopes, we carry a detailed calculation in a definite symmetry-based framework, the interacting boson model with configuration mixing (IBM-CM). We compare our calculation to a large range of experimental data, such as energy levels, two neutron separation energies, $E2$ and $E0$ transition rates, isotope shifts and magnetic moments. The structural evolution of the low lying spectra of these isotopes is explained using…
Matter radii of the $^{34-40}$Mg nuclei are investigated by self-consistent Hartree-Fock-Bogolyubov calculations assuming the axial symmetry. With the semi-realistic M3Y-P6 interaction, the $N$-dependence of the matter radii observed in the experiments is reproduced excellently. Both the pairing and the deformation play significant roles in an intertwined manner. The $^{35}$Mg nucleus has a smaller radius than the neighboring even-$N$ nuclei, which is attributed to its smaller deformation. In contrast, a neutron halo is obtained in $^{37}$Mg. We point out that, in contrast to the pairing anti-…
We introduce a new Bose-Fermi framework for studying spectral properties and quantum phase transitions (QPTs) in odd-mass nuclei, in the presence of configuration mixing. A detailed analysis of odd-mass Nb isotopes discloses the effects of an abrupt crossing of states in normal and intruder configurations (Type II QPT), accompanied by a gradual evolution from spherical- to deformed-core shapes within the intruder configuration (Type I QPT). The pronounced presence of both types of QPTs demonstrates, for the first time, the occurrence of intertwined QPTs in odd-mass nuclei.
We introduce the notion of intertwined quantum phase transitions (IQPTs), for which a crossing of two configurations coexists with a pronounced shape-evolution of each configuration. A detailed analysis in the framework of the interacting boson model with configuration mixing, provides evidence for this scenario in the Zr isotopes. The latter exhibit a normal configuration which remains spherical along the chain, but exchanges roles with an intruder configuration, which undergoes first a spherical to prolate-deformed [U(5)$\to$SU(3)] QPT and then a crossover to $γ$-unstable [SU(3)$\to$SO(6)].
Lifetime measurements in neutron-rich odd-A yttrium isotopes ($^{93-99}$Y): Investigation of shape coexistence and the intertwined quantum phase transition
Universität zu Köln（科隆大学）；Nuclear Research Center-Negev（内盖夫核科学研究中心）；Tel Aviv University（特拉维夫大学）；Institut Laue-Langevin（朗之万研究所）；Institute of Nuclear Physics, PAN（波兰科学院核物理研究所）；Institut of Physique des 2 Infinis de Lyon（里昂两无限物理研究所）；INFN Sezione di Milano（意大利国家核物理研究所米兰分部）
Solvable supersymmetric algebraic model for descriptions of the spherical to gama unstable shape- phase transition in even and odd mass nuclei is proposed. This model is based on dual algebraic structure and Richardson - Gaudin method, where the duality relations between the unitary and quasispin algebraic structures for the boson and fermion systems are extended to mixed boson- fermion system. The structure of two type of nuclear supersymmetry schemes, based on the U(6/2) and U(6/4) supergroups, is discussed. We investigate the change in level structure induced by the phase transition by doin…
We investigate the evolution of structure in the zirconium isotopes where one of the most complex situations encountered in nuclear physics occurs. We demonstrate the role of two concurrent types of quantum phase transitions, sharing a common critical point. The first type, involves an abrupt crossing of coexisting normal and intruder configurations. The second type, involves a gradual shape-phase transition within the intruder configuration, changing from weakly-deformed to prolate-deformed and finally to gamma-unstable. Evidence for this scenario is provided by a detailed comparison with exp…
In this paper, the properties of Cd(106-122)isotopes are considered in the U(5)-SO(6)transitional region of IBM1. With employing a transitional Hamiltonian which is based on affine SU(1,1)Lie Algebraic technique, the energy levels and B(E2)transition rates are calculated. The results are compared with the most recent experimental values where an acceptable degree of agreement is achieved. Also, the energy ratios, control parameters and empirical two neutron separation energies suggest spherical to gamma soft shape transitions in these nuclei where the Cd (114,122)nuclei are considered as the b…
The spherical to deformed $γ-unstable$ shape- phase transition in odd-A nuclei is investigated by using the Dual algebraic structures and the affine $SU(1,1)$ Lie Algebra within the framework of the interacting boson - fermion model. The new algebraic solution for A-odd nuclei is introduced. In this model, Single $j = 1/2 $ and $ 3/2 $ fermions are coupled with an even-even boson core. Energy spectra, quadruple electromagnetic transitions and an expectation value of the d-boson number operator are presented. Experimental evidence for the $U^{BF} (5)-O^{BF} (6)$ transition in odd -A $Ba$ and $R…
We calculate nuclear matrix elements (NME) of neutrinoless double beta decay in four different candidate nuclei (Ge-76, Se-82, Mo-100, Te-130) within the quasiparticle random phase approximation (QRPA) and its uncertainties. We assume (up to) four coexisting mechanisms for neutrinoless double beta decay, mediated by light Majorana neutrino exchange, heavy Majorana neutrino exchange, R-parity breaking supersymmetry, and squark-neutrino, interfering either constructively or destructively with each other. We find that, unfortunately, current NME uncertainties appear to prevent a robust determinat…
