TY - JOUR
T1 - Nuclear chirality, a model and the data
AU - Starosta, K.
AU - Koike, T.
N1 - Funding Information:
The first manuscript of the present article was prepared after late Prof. G E Brown had invited authors to contribute a review article on the subject to Physics Reports. At that time, both authors were engaged in experimental and theoretical work on the subject in a group lead by late Prof. D Fossan at Nuclear Structure laboratory at State University of New York at Stony Brook. The paper, however, was never published entirely due to the authors’ inability to meet the deadline for submission. In addition, this unpublished paper which remains up to this date as to be published is cited in authorʼs another paper [32]. Thus, the present paper is dedicated to Dave Fossan and Gerry Brown, and we are deeply grateful for this opportunity given by the editors not only to complete the original paper, but to go beyond it with an introduction of the proposed chiral basis. The authors would like to express their gratitude to students in the Simon Fraser University Nuclear Science group, A S Chester, J Williams and A Verma for comments and proofreading the manuscript. Financial support for this work was provided in parts by the Natural Sciences and Engineering Research Council of Canada award SAPIN/ 371656-2015.
Publisher Copyright:
© 2017 The Royal Swedish Academy of Sciences.
PY - 2017/8/24
Y1 - 2017/8/24
N2 - In the last decade, the manifestation of chirality in atomic nuclei has become the subject of numerous experimental and theoretical studies. The common feature of current model calculations is that the chiral geometry of angular momentum coupling is extracted from expectation values of orientation operators, rather than being a starting point in construction of a model. However, using the particle-hole coupling model for triaxial odd-odd nuclei it is possible to construct a basis which contains right-handed, left-handed and planar states of angular momentum coupling. If this basis is used, the chirality is an explicit rather than an extracted feature as in any other models with non-chiral bases. The time-reversal symmetry, which relates the basis states of opposite handedness, can be used to reduce the dimension of matrices for diagonalization of the model Hamiltonian, proving the effectiveness of this approach. Moreover, the final model eigenstate wave functions show a concentration of amplitudes among a relatively small number (∼1%) of components compared to the full model space. In that sense, the 'chiral' basis provides a useful tool to examine model predictions providing direct insight into the structure of doublet states. In this work, similarities and differences between the rotational behaviour of an axial and triaxial body provide a starting point for derivation of the basis optimal for valence nucleon coupling to an axial and a triaxial core. The derived 'chiral' basis is optimal for coupling of a valence particle and hole to the triaxial core. Model predictions are presented and discussed. A comprehensive review of current experimental data on observed chiral band candidates is also provided.
AB - In the last decade, the manifestation of chirality in atomic nuclei has become the subject of numerous experimental and theoretical studies. The common feature of current model calculations is that the chiral geometry of angular momentum coupling is extracted from expectation values of orientation operators, rather than being a starting point in construction of a model. However, using the particle-hole coupling model for triaxial odd-odd nuclei it is possible to construct a basis which contains right-handed, left-handed and planar states of angular momentum coupling. If this basis is used, the chirality is an explicit rather than an extracted feature as in any other models with non-chiral bases. The time-reversal symmetry, which relates the basis states of opposite handedness, can be used to reduce the dimension of matrices for diagonalization of the model Hamiltonian, proving the effectiveness of this approach. Moreover, the final model eigenstate wave functions show a concentration of amplitudes among a relatively small number (∼1%) of components compared to the full model space. In that sense, the 'chiral' basis provides a useful tool to examine model predictions providing direct insight into the structure of doublet states. In this work, similarities and differences between the rotational behaviour of an axial and triaxial body provide a starting point for derivation of the basis optimal for valence nucleon coupling to an axial and a triaxial core. The derived 'chiral' basis is optimal for coupling of a valence particle and hole to the triaxial core. Model predictions are presented and discussed. A comprehensive review of current experimental data on observed chiral band candidates is also provided.
KW - chiral coupling of angular momenta
KW - nuclear collective states
KW - nuclear models
KW - nuclear single-particle states
KW - odd and odd-odd nuclei
KW - particle-rotor model
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U2 - 10.1088/1402-4896/aa800e
DO - 10.1088/1402-4896/aa800e
M3 - Review article
AN - SCOPUS:85028768593
VL - 92
JO - Physica Scripta
JF - Physica Scripta
SN - 0031-8949
IS - 9
M1 - 093002
ER -