Multiple Chiral Doublet Bands of Identical Configuration inRh103

Abstract

Three sets of chiral doublet band structures have been identified in the 103 Rh nucleus. The properties of the observed chiral doublet bands are in good agreement with theoretical results obtained using constrained covariant density functional theory and particle rotor model calculations. Two of them belong to an identical configuration, and provide the first experimental evidence for a novel type of multiple chiral doublets, where an "excited" chiral doublet of a configuration is seen together with the "yrast" one. This observation shows that the chiral geometry in nuclei can be robust against the increase of the intrinsic excitation energy.PACS numbers: 21.10. Hw,21.10.Re,23.20.Lv A novel form of spontaneous symmetry breaking, the chiral rotation of triaxial nuclei, was suggested in 1997 [1]. It was shown that in special circumstances, referred to as chiral geometry, in the intrinsic frame of the rotating triaxial nucleus the total angular momentum vector lies outside the three principal planes. Thus, its components along the principal axes can be oriented in leftand right-handed ways. In the laboratory frame the chiral symmetry is restored, which manifests itself as a pair of ∆I = 1 nearly degenerate bands with the same parity. Such chiral doublet bands were first identified in four N = 75 isotones in 2001 [2]. So far, many chiral candidate nuclei have been reported experimentally in the A ∼ 80, 100, 130, and 190 mass regions [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Besides the simplest chiral configurations composed of one unpaired proton and neutron, composite chiral configurations, containing more than one unpaired protons and/or neutrons, have also been observed in the odd-mass or even-even neighbors of the odd-odd chiral nuclei [10,18]. These observations show that chirality is not restricted to a certain configuration in a mass region, i.e. the chiral geometry can be robust against the change of configuration. It was even demonstrated recently by Meng et al. [22][23][24][25], based on adiabatic and configuration-fixed constrained triaxial covariant density functional theory (CDFT) calculations, that it is possible to have multiple pairs of chiral doublet bands in a single nucleus, and the acronym MχD was introduced for this phenomenon. The first experimental evidence for the predicted MχD has been reported in 133 Ce [26], and also possibly in 107 Ag [27].It is also interesting to study the robustness of chiral geometry against the increase of the intrinsic excitation energy, i.e. if the chiral geometry is sustained in the higher-lying bands of a certain chiral configuration. In all the known cases the chiral doublet corresponds to the two lowest-lying bands of a configuration. Even for MχD in133 Ce [26] and 107 Ag [27], each chiral doublet structure corresponds to two lowest-lying bands with a distinct configuration. Therefore, study of the third and forth bands of the same chiral configuration is needed to answer the question of the investigated robustness. Very recent ...

Evidence for Octupole Correlations in Multiple Chiral Doublet Bands

“…The theoretical prediction of MχD bands stimulated lots of experimental efforts [27][28][29][30][31]. The first experimental evidence for MχD bands was reported in 133 Ce [27], which confirmed the manifestation of triaxial shape coexistence in this nucleus.…”

“…The first experimental evidence for MχD bands was reported in 133 Ce [27], which confirmed the manifestation of triaxial shape coexistence in this nucleus. Later, Kuti et al reported a novel type of MχD bands with the same configuration in 103 Rh [29], which showed that chiral geometry can be robust against the increase of the intrinsic excitation energy.Compared to the A ∼ 130 and 100 mass regions, the A ∼ 80 mass region is a relatively new and less studied territory for the investigation of chiral symmetry breaking in rotating nuclei, with only one report of chiral doublet bands based on the πg 9=2 ⊗ νg 9=2 configuration in odd-odd 80 Br [18]. In 78 Br, the πg 9=2 ⊗ νg 9=2 band was suggested to have an obvious triaxial shape [32], which is suitable for the construction of chiral doublet bands.…”

“…The first experimental evidence for MχD bands was reported in 133 Ce [27], which confirmed the manifestation of triaxial shape coexistence in this nucleus. Later, Kuti et al reported a novel type of MχD bands with the same configuration in 103 Rh [29], which showed that chiral geometry can be robust against the increase of the intrinsic excitation energy.…”

The limits of the nuclear landscape explored by the relativistic continuum Hartree–Bogoliubov theory

“…[64], a crucial test of the predictive power of PC-PK1 was performed by the comparison with the new and accurate experimental masses in the element range from 50 to 91 [79], and it was found that the experimental data can be reproduced quite well with a rms deviation 0.859 MeV. PC-PK1 has also been applied successfully to investigate nuclear low-lying excited states [65][66][67][68][69][70][71][72], magnetic rotation [50,[80][81][82][83], antimagnetic rotation [49,51,[84][85][86], chiral rotation modes [87], fission barrier [88], and superheavy nuclei [89], etc.…”

Tetrahedral shapes of neutron-rich Zr isotopes from a multidimensionally constrained relativistic Hartree-Bogoliubov model

“…In 2006, Meng et al predicted that multiple chiral doublet (MχD) bands may exist in one nucleus with different triaxial configurations [6]. In recent years, MχD * sgzhou@itp.ac.cn bands were indeed found in several nuclei [7][8][9][10][11]. The triaxiality may also play a role in the low-spin signature inversion [12][13][14][15][16][17].…”