Multiple Chiral Doublet Research Articles

Multiple chiral doublet bands in 104Rh

Two new negative-parity bands have been identified in the odd-odd 104Rh nucleus. According to their experimentally observed properties, they have the same π(1g9/2)−1⊗ν(1h11/2)1 high-j configuration as the previously known negative-parity chiral doublet bands. This observation raises the possibility of the existence of multiple chiral doublet bands, MχD, in this nucleus. Comparing the properties of the observed bands with results of detailed theoretical calculations, one can conclude that the lower energy parts of bands 1 and 2 are chiral partner bands with the π(1g9/2)−1⊗ν(1h11/2)1 two-quasiparticle configuration, while bands 3 and 4 are chiral partner bands with the π(1g9/2)−1⊗ν(1g7/2)−2(1h11/2)1 four-quasiparticle configuration. Thus, MχD based on different configurations is observed in 104Rh.

Rotational spectroscopies of reflection-asymmetric nuclei within particle rotor model

The rotational spectroscopic properties of reflection-asymmetric nuclei investigated by the reflection-asymmetric axial or triaxial particle rotor model are briefly reviewed. The status of observations of the alternated parity bands in even–even nuclei and the parity doublet bands in odd-[Formula: see text] and odd–odd nuclei for the [Formula: see text] mass region are summarized. The reflection-asymmetric axial particle rotor model has been used to systematically describe the parity doublet bands of the odd-[Formula: see text] nuclei in this region. With the triaxial degree of freedom included, the reflection-asymmetric triaxial particle rotor model shows the ability to study the multiple chiral doublet bands with octupole correlations and explore the possible chirality-parity quartet bands.

Possible wobbling motion in multiple chiral doublets

The analysis of mixing ratios δ of the ΔI =1 linking transitions in the chiral and multiple chiral doublet bands with the ideal case are theoretically performed for the first time by employing the quantum particle rotor model. The calculated E2 fraction extracted from the mixing ratio show that the ΔI =1 linking transitions in the lowest and excited chiral doublet bands are of the pure M1 character, while those connecting the excited to lowest chiral doublet bands are of M1/E2 character with a relatively large E2 admixture. The further analysis of the angular momentum geometry and azimuthal plots reveals that the excited chiral doublet bands represents a chiral geometry with a wobbling motion of the core. This provides a possible figure of wobbling motion in multiple chiral doublets.

Possible existence of chiral and multiple chiral nuclei in thallium isotopes * *This work is partly support by the Major Program of Natural Science Foundation of Shandong Province (ZR2020ZD30), the Outstanding Youth Fund of Natural Science Foundation of Shandong Province (ZR2020YQ07), the National Natural Science Foundation of China (11675094, 12075138), and the Young Scholars Program of Shandong University, Weihai. The

The chirality in thallium isotopes is investigated using the adiabatic and configuration-fixed constrained triaxial relativistic mean field theory. Several minima with prominent triaxial deformation and proper configuration, where the chiral doublet bands may appear, are obtained in odd-odd nuclei Tl and odd-mass nuclei Tl. Furthermore, the possible existence of multiple chiral doublet bands (MχD) is demonstrated in Tl. As the chiral doublet bands in Tl and MχD in 195Tl have been observed experimentally, further experimental exploration for the chirality in Tl and MχD in thallium isotopes is expected to verify the predictions.

First observation of the coexistence of multiple chiral doublet bands and pseudospin doublet bands in the A ≈ 80 mass region

Two nearly degenerate positive-parity bands with the πg9/22⊗νg9/2−1 configuration and three nearly degenerate negative-parity bands with the πg9/2(p3/2,f5/2)⊗νg9/2−1 configuration have been identified in 81Kr. They are interpreted as chiral doublet bands and pseudospin-chiral triplet bands, which is supported by the constrained covariant density functional theory and the multiparticle plus rotor model calculations. The present work reports two new chiral configurations πg9/22⊗νg9/2−1 and πg9/2(p3/2,f5/2)⊗νg9/2−1, and the first example of pseudospin-chiral triplet bands involving the π(p3/2,f5/2) pseudospin doublet.

Critical point symmetry for odd-odd nuclei and collective multiple chiral doublet bands

Critical point symmetry for odd-odd nuclei and collective multiple chiral doublet bands

Erratum: Chirality of Nd135 reexamined: Evidence for multiple chiral doublet bands [Phys. Rev. C 100 , 024314 (2019)

Erratum: Chirality of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Nd</mml:mi><mml:mprescripts /><mml:none /><mml:mn>135</mml:mn></mml:mmultiscripts></mml:math> reexamined: Evidence for multiple chiral doublet bands [Phys. Rev. C <b>100</b> , 024314 (2019)

Possible Candidates for Chirality in the Odd-Odd As IsotopesSupported by the National Natural Science Foundation of China (Grant Nos. 11705102 and 11675094), the Shandong Natural Science Foundation (Grant No. JQ201701), and the Young Scholars Program of Shandong University, Weihai.

The deformations and the corresponding configurations of the odd-odd As isotopes are investigated using the adiabatic and configuration-fixed constrained triaxial relativistic mean field (RMF) theory. Energy minima with triaxial deformations and high-j particle-hole configurations are obtained in 72,74,76,78,80As, where the chiral doublet bands are possible to appear. The existence of multiple chiral doublet (MχD) is demonstrated in 74,76,78As. Based on the calculated single-particle levels, we also find possible coexistence of chiral and pseudospin symmetries in the odd-odd As isotopes.

Recent progress in multiple chiral doublet bands * * Supported by the Shandong Natural Science Foundation, China (JQ201701) and the National Natural Science Foundation of China (11622540)

Recent progress regarding multiple chiral doublet bands ( ) is reviewed from the experimental and theoretical perspectives. In particular, the experimental findings, theoretical predictions, selection rule for electromagnetic transitions, with octupole correlations, and some related topics are highlighted. Based on these discussions, it is of great scientific interest to search for the other , as well as possible chiral wobblers, chirality-parity quartet bands, and chirality-pseudospin triplet (or quartet) bands in the nuclear system.

Pseudospin symmetry and octupole correlations for multiple chiral doublets in Ba131

A reflection-asymmetric triaxial particle rotor model with three quasiparticles and a reflection-asymmetric triaxial rotor is developed, and applied to investigate the observed multiple chiral doublets (M\c{hi}D) candidates with octupole correlations in 131Ba, i.e., two pairs of positive-parity bands D3-D4 and D5-D6, as well as one pair of negative-parity bands D7-D8. The energy spectra, the energy staggering parameters, the B(M1)/B(E2) ratios, and the B(E1)/B(E2) ratios are reproduced well. The chiral geometries for these M\c{hi}D candidates are examined by the azimuthal plots, and the evolution of chiral geometry with spin is clearly demonstrated. The intrinsic structure for the positive-parity bands is analyzed and the possible pseudospin-chiral quartet bands are suggested.

Novel Excitation Modes in Nuclei: Experimental and Theoretical Investigation on Multiple Chiral Doublets

As a microscopic quantal many-body system, the structure of atomic nucleus is understood by measuring and interpreting its responses to all kinds of probes. The responses manifest in different kinds of energy excitation spectra with specific energy and angular momentum (spin), and link with electric and magnetic transition rates.

Chirality of Nd135 reexamined: Evidence for multiple chiral doublet bands

One new pair of positive-parity chiral doublet bands have been identified in the odd-A nucleus Nd135 which together with the previously reported negative-parity chiral doublet bands constitute a third case of multiple chiral doublet (MχD) bands in the A≈130 mass region. The properties of the MχD bands are well reproduced by constrained covariant density functional theory and particle rotor model calculations. The newly observed MχD bands in Nd135 represents an important milestone in supporting the existence of MχD in nuclei.Received 6 April 2019Revised 23 May 2019DOI:https://doi.org/10.1103/PhysRevC.100.024314©2019 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasCollective levelsCollective modelsElectromagnetic transitionsNuclear spin & parityNuclear structure & decaysNuclear Physics

Multiple chiral doublet bands with octupole correlations in reflection-asymmetric triaxial particle rotor model

A reflection-asymmetric triaxial particle rotor model (RAT-PRM) with a quasi-proton and a quasi-neutron coupled with a reflection-asymmetric triaxial rotor is developed and applied to investigate the multiple chiral doublet (MχD) bands candidates with octupole correlations in 78Br. The calculated excited energies, energy staggering parameters, and B(M1)/B(E2) ratios are in a reasonable agreement with the data of the chiral doublet bands with positive- and negative-parity. It is found that both the triaxial deformation γ and octupole deformation β3 influence the calculated B(E1) values. The chiral geometry based on the angular momenta for the rotor, the valence proton and valence neutron is discussed in details.

Candidate chiral nuclei in bromine isotopes based on triaxial relativistic mean field theory

Following the observation of candidate chiral doublet bands in $^{78,80}$Br, triaxial deformations with corresponding configurations in odd-odd bromine isotopes have been investigated using adiabatic and configuration-fixed constrained triaxial relativistic-mean-field calculations with an aim of finding the boundary of chirality in the chain of Br isotopes. Several minima with triaxial deformation and the proper particle-hole configuration were obtained in $^{74,76,78,80,82}$Br, where the chiral doublet bands have the possibility of occurrence. Furthermore, the possible existence of multiple chiral doublet (M$\chi$D) bands is demonstrated in $^{74,76,78,80,82}$Br. Experiments to explore the chirality and M$\chi$D properties of Br isotopes are conducted to verify the predictions.

Nuclear chiral doublet bands data tables

Since the prediction of nuclear chirality in 1997, tremendous progresses both theoretically and experimentally have been achieved. Experimentally, 59 chiral doublet bands in 47 chiral nuclei (including 8 nuclei with multiple chiral doublets) have been reported in A∼80,100,130, and 190 mass regions. The spins, parities, energies, ratios of the magnetic dipole transition strengths to the electric quadrupole transition strengths, and related references for these nuclei are compiled and listed. For these nuclei with the magnetic dipole transition strengths and the electric quadrupole transition strengths measured, the corresponding results are given. A brief discussion is provided after the presentation of energy E, energy difference ΔE, energy staggering parameter S(I), rotational frequency ω, kinematic moment of inertia J(1), dynamic moment of inertia J(2), and ratio of the magnetic dipole transition strength to the electric quadrupole transition strength B(M1)∕B(E2) versus spin I in each mass region.

Multiple chiral doublets in four-j shells particle rotor model: Five possible chiral doublets in [formula omitted]Nd76

A particle rotor model, which couples nucleons in four single-j shells to a triaxial rotor core, is developed to investigate the five pairs of nearly degenerate doublet bands recently reported in the even-even nucleus 136Nd. The experimental energy spectra and available B(M1)/B(E2) values are successfully reproduced. The angular momentum geometries of the valence nucleons and the core support the chiral rotation interpretations not only for the previously reported chiral doublet, but also for the other four candidates. Hence, 136Nd is the first even-even candidate nucleus in which the multiple chiral doublets exist. Five pairs of chiral doublet bands in a single nucleus is also a new record in the study of nuclear chirality.

Possible candidates for multiple chiral doublet bands in cesium isotopes

Following the reports of candidate chiral doublet bands observed in odd-$A$ cesium isotopes, the triaxial deformations with corresponding configuration and the possible multiple chiral doublet ($\mathrm{M}\ensuremath{\chi}\mathrm{D}$) phenomenon in $^{125,127,129,131}\mathrm{Cs}$ are investigated within the adiabatic and configuration-fixed constrained triaxial relativistic mean-field (RMF) calculations. The existence of the $\mathrm{M}\ensuremath{\chi}\mathrm{D}$ phenomenon in $^{125,129,131}\mathrm{Cs}$ is demonstrated and expected based on different high-$j$ particle-hole configurations and triaxial deformations.

Multiple Chiral Doublet Bands and Possible Transverse Wobbling Near $^{104}$Rh

Multiple Chiral Doublet Bands and Possible Transverse Wobbling Near $^{104}$Rh

Fission barriers from multidimensionally-constrained covariant density functional theories

In recent years, we have developed the multidimensionally-constrained covariant density functional theories (MDC-CDFTs) in which both axial and spatial reflection symmetries are broken and all shape degrees of freedom described by β λμ with even μ , such as β 20 , β 22 , β 30 , β 32 , β 40 , etc., are included self-consistently. The MDC-CDFTs have been applied to the investigation of potential energy surfaces and fission barriers of actinide nuclei, third minima in potential energy surfaces of light actinides, shapes and potential energy surfaces of superheavy nuclei, octupole correlations between multiple chiral doublet bands in 78 Br, octupole correlations in Ba isotopes, the Y 32 correlations in N = 150 isotones and Zr isotopes, the spontaneous fission of Fm isotopes, and shapes of hypernuclei. In this contribution we present the formalism of MDC-CDFTs and the application of these theories to the study of fission barriers and potential energy surfaces of actinide nuclei.

Electromagnetic transitions in multiple chiral doublet bands**Supported by National Natural Science Foundation of China (11675094, 11622540, 11545011, 11405096, 11461141001, U1432119), Shandong Natural Science Foundation (ZR2014AQ012), and Young Scholars Program of Shandong University, Weihai (2015WHWLJH01)

Multiple chiral doublet bands (MχD) in the 80, 130 and 190 mass regions are studied by the model of γ = 90° triaxial rotor coupled with identical symmetric proton-neutron configurations. By selecting a suitable basis, the calculated wave functions are explicitly exhibited to be symmetric under the operator Â, which is defined as rotation by 90° about the 3-axis with the exchange of valance proton and neutron. We found that both M1 and E2 transitions are allowed between levels with different values of A, while they are forbidden between levels with same values of A. Such a selection rule holds true for MχD in different mass regions.