86 results on '"Q. B. Chen"'
Search Results
2. Deformation and hyperon halo in hypernuclei
- Author
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Huai-Tong Xue, Q. B. Chen, Xian-Rong Zhou, Y. Y. Cheng, and H.-J. Schulze
- Published
- 2022
3. Publisher Erratum: Study of wobbling modes by means of spin coherent state maps
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Q. B. Chen and S. Frauendorf
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Nuclear and High Energy Physics - Published
- 2022
4. Single-particle and collective excitations in Zn66
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A. D. Ayangeakaa, N. Sensharma, M. Fulghieri, R. V. F. Janssens, Q. B. Chen, S. Zhu, M. Alcorta, M. P. Carpenter, P. Chowdhury, A. Gade, C. R. Hoffman, F. G. Kondev, T. Lauritsen, E. A. McCutchan, A. M. Rogers, and D. Seweryniak
- Published
- 2022
5. Evolution of the chiral rotation mode in rhodium isotopes
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J. Peng and Q. B. Chen
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- 2022
6. Single-particle and dipole excitations in Co62
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N. Sensharma, A. D. Ayangeakaa, R. V. F. Janssens, Q. B. Chen, S. Zhu, M. Alcorta, M. P. Carpenter, E. A. McCutchan, F. G. Kondev, T. Lauritsen, D. Seweryniak, C. R. Hoffman, A. M. Rogers, A. Gade, T. Baugher, and P. Chowdhury
- Published
- 2022
7. ΛΛ pairing effects in spherical and deformed multi- Λ hyperisotopes
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Jing Guo, C. F. Chen, Xian-Rong Zhou, Q. B. Chen, and H.-J. Schulze
- Published
- 2022
8. Lambda binding energies in the Skyrme-Hartree-Fock approach with various $$\Lambda N$$ interactions
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Yi-Fan Chen, Xian-Rong Zhou, Q. B. Chen, and Yi-Yuan Cheng
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Nuclear and High Energy Physics - Published
- 2022
9. Novel Excitation Modes in Nuclei: Experimental and Theoretical Investigation on Multiple Chiral Doublets
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Q. B. Chen and Jie Meng
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Physics ,Nuclear and High Energy Physics ,010308 nuclear & particles physics ,0103 physical sciences ,Atomic nucleus ,010306 general physics ,01 natural sciences ,Molecular physics ,Excitation - Abstract
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 kind...
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- 2020
10. Possible existence of multiple wobbling modes in A≈60 nuclei
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L. Hu, J. Peng, and Q. B. Chen
- Published
- 2021
11. Evidence of octupole correlation in Se79
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S. Rajbanshi, R. Palit, R. Raut, Y. Y. Wang, Z. X. Ren, J. Meng, Q. B. Chen, Sajad Ali, H. Pai, F. S. Babra, R. Banik, S. Bhattacharya, S. Bhattacharyya, P. Dey, S. Malik, G. Mukherjee, Md. S. R. Laskar, S. Nandi, Rajkumar Santra, T. Trivedi, S. S. Ghugre, and A. Goswami
- Published
- 2021
12. [Mid-and-long term follow-up of autogenous tibial periosteum-bone complex transplantation for treatment of cystic osteochondral lesion of talus]
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Y, Tang, C S, Yuan, W, Chen, Q B, Chen, X, Tao, and K L, Tang
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Adult ,Male ,Bone Transplantation ,Treatment Outcome ,Periosteum ,Humans ,Female ,Middle Aged ,Follow-Up Studies ,Talus - Published
- 2021
13. Two-phonon wobbling in 135Pr
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Q. B. Chen, N. Sensharma, A. D. Ayangeakaa, Y. K. Gupta, D. Seweryniak, J. L. Cozzi, J. Sethi, R. V. F. Janssens, F. G. Kondev, G. H. Bhat, S. S. Ghugre, D. J. Hartley, M. P. Carpenter, S. Zhu, J. A. Sheikh, R. P. Singh, S. Frauendorf, K. B. Howard, R. Palit, Wei Li, T. C. McMaken, and U. Garg
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Physics ,Nuclear and High Energy Physics ,Condensed matter physics ,010308 nuclear & particles physics ,Rotor (electric) ,Phonon ,Shell (structure) ,Conclusive evidence ,01 natural sciences ,lcsh:QC1-999 ,law.invention ,Transverse plane ,medicine.anatomical_structure ,Character (mathematics) ,law ,0103 physical sciences ,Quasiparticle ,medicine ,010306 general physics ,Nucleus ,lcsh:Physics - Abstract
The second-phonon ( n ω = 2 ) wobbling band has been established in the nucleus 135Pr. Conclusive evidence for its wobbling nature comes from the Δ I = 1 , E2 character of the transitions between the new band and the previously identified transverse wobbler band ( n ω = 1 ) in this nucleus. Theoretical calculations in the framework of the quasiparticle triaxial rotor and triaxial projected shell models are found to be in good agreement with the experimental results.
- Published
- 2019
14. Effects of a kaonic meson on the ground-state properties of nuclei *
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Jing Guo, D. H. Chen, Xian-Rong Zhou, Q. B. Chen, and H.-J. Schulze
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Nuclear and High Energy Physics ,Nuclear Theory ,Astronomy and Astrophysics ,Nuclear Experiment ,Instrumentation - Abstract
The effects of an additional meson on the ground-state properties of nuclei are investigated within an axially-deformed Skyrme-Hartree-Fock approach combined with a Skyrme-type kaon-nucleon interaction. The meson increases the binding energies of all nuclei, whereas it affects deformations only for light nuclei without shell closure. The nucleon drip lines are modified due to the strongly attractive interaction. This is attributed to the behavior of the highest-occupied nucleon single-particle levels near the drip lines, which is analyzed in detail.
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- 2022
15. Erratum: Chirality of Nd135 reexamined: Evidence for multiple chiral doublet bands [Phys. Rev. C 100 , 024314 (2019)]
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S. Juutinen, X. H. Zhou, T. Calverley, J. Srebrny, Huan Liu, Q. B. Chen, Jianlu Wang, István Kuti, Paul Greenlees, Jie Meng, Juha Uusitalo, Song Guo, Juha Sorri, Sanna Stolze, M. L. Liu, J. Konki, C. Scholey, Jukka Partanen, Daniel Cox, C. M. Petrache, József Tímár, Jan Sarén, A. Astier, P. Rahkila, E. Dupont, R. Julin, A. Tucholski, H. Badran, Bo Cederwall, A. Ertoprak, P. Ruotsalainen, J. Pakarinen, Corina Andreoiu, B. F. Lv, M. Sandzelius, T. Grahn, Philippos Papadakis, and J. Hilton
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Physics ,Condensed matter physics ,Chirality (chemistry) - Published
- 2021
16. $g$-factor and static quadrupole moment of $^{135}$Pr, $^{105}$Pd, and $^{187}$Au in wobbling motion
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C. Broocks, Norbert Kaiser, Q. B. Chen, and Ulf-G. Meißner
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Physics ,Nuclear and High Energy Physics ,Nuclear Theory ,010308 nuclear & particles physics ,g factor ,Yrast ,Hadron ,Motion (geometry) ,FOS: Physical sciences ,01 natural sciences ,Nuclear Theory (nucl-th) ,Total angular momentum quantum number ,0103 physical sciences ,Quadrupole ,Nuclear fusion ,ddc:530 ,Atomic physics ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Spin (physics) ,Nuclear Experiment - Abstract
The $g$-factor and static quadrupole moment of the nuclides $^{135}$Pr, $^{105}$Pd, and $^{187}$Au in the wobbling motion are investigated in the particle-rotor model as functions of the total spin $I$. The $g$-factor of $^{105}\mathrm{Pd}$ increases with increasing $I$, due to the negative gyromagnetic ratio of a neutron valence-neutron. This behavior is in contrast to the decreasing $g$-factor of the other two nuclides, $^{135}$Pr and $^{187}$Au, which feature a valence-proton. The static quadrupole moment $Q$ depends on all three expectation values of the total angular momentum. It is smaller in the yrast band than in the wobbling band for the transverse wobblers $^{135}$Pr and $^{105}$Pd, while larger for the longitudinal wobbler $^{187}$Au., Comment: 6 pages, 4 figures
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- 2021
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17. Pseudo spin doublet bands and Gallagher Moszkowski doublet bands in $^{100}$Y
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E. H. Wang, J. H. Hamilton, A. V. Ramayya, C. J. Zachary, A. Lemasson, A. Navin, M. Rejmund, S. Bhattacharyya, Q. B. Chen, S. Q. Zhang, J. M. Eldridge, J. K. Hwang, N. T. Brewer, Y. X. Luo, J. O. Rasmussen, S. J. Zhu, G. M. Ter-Akopian, Yu. Ts. Oganessian, M. Caamaño, E. Clément, O. Delaune, F. Farget, G. de France, B. Jacquot, Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
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Physics ,Spin states ,Spectrometer ,Nuclear Theory ,Pseudo Spin ,[PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th] ,Fission ,FOS: Physical sciences ,[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] ,Nuclear Structure ,Coincidence ,Nuclear Theory (nucl-th) ,100Y ,Gammasphere ,Covariant transformation ,Atomic physics ,Nuclear Experiment (nucl-ex) ,Electronic band structure ,Nuclear Experiment ,GM Partner ,Spontaneous fission - Abstract
New transitions in neutron rich $^{100}$Y have been identified in a $^9$Be+$^{238}$U experiment with mass- and Z- gates to provide full fragment identification. These transitions and high spin levels of $^{100}$Y have been investigated by analyzing the high statistics $\gamma$-$\gamma$-$\gamma$ and $\gamma$-$\gamma$-$\gamma$-$\gamma$ coincidence data from the spontaneous fission of $^{252}$Cf at the Gammasphere detector array. Two new bands, 14 new levels and 23 new transitions have been identified. The $K^{\pi}=4^+$ new band decaying to an 1s isomeric state is assigned to be the high-$K$ Gallagher-Moszkowski (GM) partner of the known $K^{\pi}=1^+$ band, with the $\pi 5/2[522] \otimes \nu 3/2[411]$ configuration. This 4$^+$ band is also proposed to be the pseudo spin partner of the new $K^{\pi}=5^+$ band with a 5$^{+}$ $\pi 5/2[422] \otimes \nu 5/2[413]$ configuration, to form a $\pi 5/2[422] \otimes \nu [312$ $5/2,3/2]$ neutron pseudospin doublet. Constrained triaxial covariant density functional theory and quantal particle rotor model calculations have been applied to interpret the band structure and available electromagnetic transition probabilities and are found in good agreement with experimental values.
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- 2021
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18. Prolate-to-oblate transition and backbending along the yrast line induced by quasiparticle alignment
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Q. B. Chen and Fang-Qi Chen
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Physics ,Condensed Matter::Quantum Gases ,Nuclear and High Energy Physics ,Nuclear Theory ,Condensed matter physics ,010308 nuclear & particles physics ,Yrast ,FOS: Physical sciences ,Prolate spheroid ,01 natural sciences ,lcsh:QC1-999 ,Nuclear Theory (nucl-th) ,Mean field theory ,Atomic orbital ,0103 physical sciences ,Oblate spheroid ,Quasiparticle ,Physics::Atomic and Molecular Clusters ,010306 general physics ,Nuclear Experiment ,Nuclear theory ,lcsh:Physics ,Line (formation) - Abstract
The yrast lines in Kr isotopes with $N=42$, 44, and 46 are investigated in a beyond mean field framework with both prolate-oblate coexistence and quasiparticle alignment taken into account. Quasiparticle orbitals with high-$j$ and low-$\Omega$ on the oblate side are shown to be responsible for the sharp backbending observed in $^{82}$Kr, by driving the yrast shape from prolate to oblate. This suggests that quasiparticle alignment may not be neglected in the investigation of the shape evolution along the yrast line., Comment: 6 pages, 5figiures
- Published
- 2020
19. First Observation of Multiple Transverse Wobbling Bands of Different Kinds in Au183
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Sajad Ali, Sumita Bhattacharyya, Q. B. Chen, G. Mukherjee, S. Samanta, S. Chatterjee, S. Nandi, S. Das, Shabir Dar, Anindya Goswami, P. Chowdhury, R. Banik, S. Das Gupta, Md. A. Asgar, H. Pai, R. Raut, C. Bhattacharya, Soumik Bhattacharya, S. S. Ghugre, S. Rajbanshi, and S. Frauendorf
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Physics ,Linear polarization ,Nuclear Theory ,General Physics and Astronomy ,Parity (physics) ,01 natural sciences ,Physics::Geophysics ,Transverse plane ,medicine.anatomical_structure ,0103 physical sciences ,medicine ,Atomic physics ,010306 general physics ,Nucleus - Abstract
We report the first observation of two wobbling bands in ^{183}Au, both of which were interpreted as the transverse wobbling (TW) band but with different behavior of their wobbling energies as a function of spin. It increases (decreases) with spin for the positive (negative) parity configuration. The crucial evidence for the wobbling nature of the bands, dominance of the E2 component in the ΔI=1 transitions between the partner bands, is provided by the simultaneous measurements of directional correlation from the oriented states ratio and the linear polarization of the γ rays. Particle rotor model calculations with triaxial deformation reproduce the experimental data well. A value of spin, I_{m}, has been determined for the observed TW bands below which the wobbling energy increases and above which it decreases with spin. The nucleus ^{183}Au is, so far, the only nucleus in which both the increasing and the decreasing parts are observed and thus gives the experimental evidence of the complete transverse wobbling phenomenon.
- Published
- 2020
20. Static quadrupole moments of nuclear chiral doublet bands
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Jie Meng, Norbert Kaiser, Ulf-G. Meißner, and Q. B. Chen
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Physics ,Nuclear and High Energy Physics ,Nuclear Theory ,010308 nuclear & particles physics ,High Energy Physics::Phenomenology ,FOS: Physical sciences ,01 natural sciences ,lcsh:QC1-999 ,ddc ,Vibration ,Nuclear Theory (nucl-th) ,0103 physical sciences ,Quadrupole ,ddc:530 ,Atomic physics ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Chirality (chemistry) ,Nuclear Experiment ,Nuclear theory ,lcsh:Physics - Abstract
The static quadrupole moments (SQMs) of nuclear chiral doublet bands are investigated for the first time taking the particle-hole configuration $\pi(1h_{11/2}) \otimes \nu(1h_{11/2})^{-1}$ with triaxial deformation parameters in the range $260^\circ \leq \gamma \leq 270^\circ$ as examples. The behavior of the SQM as a function of spin $I$ is illustrated by analyzing the components of the total angular momentum. It is found that in the region of chiral vibrations the SQMs of doublet bands are strongly varying with $I$, whereas in the region of static chirality the SQMs of doublet bands are almost constant. Hence, the measurement of SQMs provides a new criterion for distinguishing the modes of nuclear chirality. Moreover, in the high-spin region the SQMs can be approximated by an analytic formula with a proportionality to $\cos\gamma$ for both doublet bands. This provides a way to extract experimentally the triaxial deformation parameter $\gamma$ for chiral bands from the measured SQMs., Comment: 7 pages, 4 figures
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- 2020
21. Coexistence of planar and aplanar rotations in $^{195}$Tl
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J. Peng and Q. B. Chen
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Physics ,Nuclear and High Energy Physics ,Angular momentum ,Nuclear Theory ,010308 nuclear & particles physics ,FOS: Physical sciences ,Rotation ,01 natural sciences ,Molecular physics ,lcsh:QC1-999 ,Spectral line ,ddc ,Nuclear Theory (nucl-th) ,Planar ,0103 physical sciences ,Chirality (mathematics) ,Covariant transformation ,Density functional theory ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Nuclear Experiment ,lcsh:Physics ,Rotor (mathematics) - Abstract
The chirality suggested for the doublet bands B2 and B2a in $^{195}$Tl in $A\sim190$ region is reexamined. The potential-energy curves and the configurations together with the deformation parameters are obtained by the constrained covariant density functional theory. The corresponding experimental energy spectra, energy differences between doublet bands, and the available $B(M1)/B(E2)$ values are investigated by the fully quantal particle rotor model. Analysis on the basis of the angular momentum components, the $K$-plots, and the azimuthal plots suggest a planar rotation interpretation for the bands B2 and B2a. Hence, it coexists with the aplanar rotation in the other doublet bands B4 and B4a in $^{195}$Tl., Comment: 7 pages, 5 figures. arXiv admin note: text overlap with arXiv:1904.12100
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- 2020
- Full Text
- View/download PDF
22. $g$-factor and static quadrupole moment for the wobbling mode in $^{133}$La
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Q. B. Chen, Jie Meng, Norbert Kaiser, S. Frauendorf, and Ulf-G. Meißner
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Nuclear and High Energy Physics ,Angular momentum ,Nuclear Theory ,FOS: Physical sciences ,01 natural sciences ,law.invention ,Nuclear Theory (nucl-th) ,law ,Total angular momentum quantum number ,0103 physical sciences ,ddc:530 ,Nuclear Experiment (nucl-ex) ,Nuclear Experiment ,010306 general physics ,Spin (physics) ,Physics ,010308 nuclear & particles physics ,Rotor (electric) ,Yrast ,g-factor ,lcsh:QC1-999 ,ddc ,Quadrupole ,Atomic physics ,lcsh:Physics ,Excitation - Abstract
The $g$-factor and static quadrupole moment for the wobbling mode in the nuclide $^{133}$La are investigated as functions of the spin $I$by employing the particle rotor model. The model can reproduce the available experimental data of $g$-factor and static quadrupole moment. The properties of the $g$-factor and static quadrupole moment as functions of $I$ are interpreted by analyzing the angular momentum geometry of the collective rotor, proton-particle, and total nuclear system. It is demonstrated that the experimental value of the $g$-factor at the bandhead of the yrast band leads to the conclusion that the rotor angular momentum is $R\simeq 2$. Furthermore, the variation of the $g$-factor with the spin $I$ yields the information that the angular momenta of the proton-particle and total nuclear system are oriented parallel to each other. The negative values of the static quadrupole moment over the entire spin region are caused by an alignment of the total angular momentum mainly along the short axis. Static quadrupole moment differences between the wobbling and yrast band originate from a wobbling excitation with respect to the short axis., Comment: 6 pages, 4 figures
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- 2020
- Full Text
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23. Multiple chiral bands in $^{137}$Nd
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Bo Cederwall, Panu Rahkila, Tuomas Grahn, J. Hilton, Daniel Cox, Juha Uusitalo, Paul Greenlees, Song Guo, Corina Andreoiu, István Kuti, A. Tucholski, Jie Meng, S. Stolze, Rauno Julin, Xiaojuan Zhou, C. M. Petrache, Jie Wang, K. K. Zheng, Mikael Sandzelius, Q. B. Chen, H. Badran, A. Ertoprak, Joonas Konki, Philippos Papadakis, J. Srebrny, Jan Sarén, Jari Partanen, Janne Pakarinen, T. Calverley, A. Astier, Panu Ruotsalainen, E. Dupont, B. F. Lv, Sakari Juutinen, Juha Sorri, Huan Liu, Catherine Scholey, János Timár, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
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Physics ,Nuclear and High Energy Physics ,nucl-th ,Nuclear Theory ,Series (mathematics) ,010308 nuclear & particles physics ,Hadron ,FOS: Physical sciences ,[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] ,nucl-ex ,01 natural sciences ,Molecular physics ,Nuclear Theory (nucl-th) ,Nuclear Physics - Theory ,0103 physical sciences ,Nuclear fusion ,Nuclear Physics - Experiment ,Density functional theory ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Spectroscopy ,Nuclear Experiment - Abstract
Two new bands have been identified in $^{137}$Nd from a high-statistics JUROGAM II gamma-ray spectroscopy experiment. Constrained density functional theory and particle rotor model calculations are used to assign configurations and investigate the band properties, which are well described and understood. It is demonstrated that these two new bands can be interpreted as chiral partners of previously known three-quasiparticle positive- and negative-parity bands. The newly observed chiral doublet bands in $^{137}$Nd represent an important support to the existence of multiple chiral bands in nuclei. The present results constitute the missing stone in the series of Nd nuclei showing multiple chiral bands, which becomes the most extended sequence of odd–even and even-even nuclei presenting multiple chiral bands in the Segré chart. Two new bands have been identified in $^{137}$Nd from a high-statistics JUROGAM II gamma-ray spectroscopy experiment. Constrained density functional theory and particle rotor model calculations are used to assign configurations and investigate the band properties, which are well described and understood. It is demonstrated that these two new bands can be interpreted as chiral partners of previously known three-quasiparticle positive- and negative-parity bands. The newly observed chiral doublet bands in $^{137}$Nd represent an important support to the existence of multiple chiral bands in nuclei. The present results constitute the missing stone in the series of Nd nuclei showing multiple chiral bands, which becomes the most extended sequence of nuclei presenting multiple chiral bands in the Segr\'e chart.
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- 2020
- Full Text
- View/download PDF
24. Pseudospin partner bands in Ba 130
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C. M. Petrache, D. Mengoni, Song Guo, Q. B. Chen, István Kuti, Corina Andreoiu, B. Ding, S. Riccetto, Jianlu Wang, D. Bazzacco, F. H. Garcia, Y. X. Liu, E. A. Lawrie, A. Tucholski, A. Goasduff, D. R. Napoli, T. Marchlewski, E. Dupont, K. K. Zheng, G. Jaworski, M. L. Liu, D. Sohler, J. J. Valiente-Dobón, Y. H. Qiang, K. Whitmore, F. Galtarossa, Bo Cederwall, X. H. Zhou, B. F. Lv, M. Siciliano, J. Srebrny, A. Astier, K. Ortner, A. Boso, Y. D. Fang, D. A. Testov, and F. Recchia
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Physics ,Condensed matter physics ,010308 nuclear & particles physics ,0103 physical sciences ,010306 general physics ,01 natural sciences - Published
- 2020
25. First Observation of Multiple Transverse Wobbling Bands of Different Kinds in $^{183}$Au
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S, Nandi, G, Mukherjee, Q B, Chen, S, Frauendorf, R, Banik, Soumik, Bhattacharya, Shabir, Dar, S, Bhattacharyya, C, Bhattacharya, S, Chatterjee, S, Das, S, Samanta, R, Raut, S S, Ghugre, S, Rajbanshi, Sajad, Ali, H, Pai, Md A, Asgar, S, Das Gupta, P, Chowdhury, and A, Goswami
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Quantitative Biology::Biomolecules ,Nuclear Theory ,FOS: Physical sciences ,Nuclear Experiment (nucl-ex) ,Nuclear Experiment ,Physics::Geophysics - Abstract
We report the first observation of two wobbling bands in $^{183}$Au, both of which were interpreted as the transverse wobbling (TW) band but with different behavior of their wobbling energies as a function of spin. It increases (decreases) with spin for the positive (negative) parity configuration. The crucial evidence for the wobbling nature of the bands, dominance of the $E2$ component in the $\Delta I = 1$ transitions between the partner bands, is provided by the simultaneous measurements of directional correlation from the oriented states (DCO) ratio and the linear polarization of the $\gamma$ rays. Particle rotor model calculations with triaxial deformation reproduce the experimental data well. A value of spin, $I_m$, has been determined for the observed TW bands below which the wobbling energy increases and above which it decreases with spin. The nucleus $^{183}$Au is, so far, the only nucleus in which both the increasing and the decreasing parts are observed and thus gives the experimental evidence of the complete transverse wobbling phenomenon., Comment: 6 pages, 5 figures, Accepted in Physical Review Letters
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- 2020
- Full Text
- View/download PDF
26. Multiple chiral doublets in four-j shells particle rotor model: Five possible chiral doublets in 60136Nd76
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Q. B. Chen, B. F. Lv, Jie Meng, and C. M. Petrache
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Physics ,Nuclear and High Energy Physics ,Angular momentum ,Valence (chemistry) ,010308 nuclear & particles physics ,Nuclear Theory ,High Energy Physics::Phenomenology ,Degenerate energy levels ,01 natural sciences ,Molecular physics ,Spectral line ,medicine.anatomical_structure ,0103 physical sciences ,medicine ,Nuclear Experiment ,010306 general physics ,Nucleon ,Chirality (chemistry) ,Nucleus ,Nuclear theory - Abstract
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 ( M 1 ) / B ( E 2 ) 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.
- Published
- 2018
27. 'Stapler' mechanism for a dipole band in Se79
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Z. Q. Chen, J.F. Sharpey-Schafer, Xiaocan Li, H. Y. Wu, N. A. Khumalo, D. W. Luo, Shuangxi Wang, T. D. Bucher, Jie Meng, Peter B. Jones, R. Han, S. Y. Wang, Y. L. Ye, D. X. Jiang, C. Xu, Hui Hua, K. L. Malatji, S. M. Wyngaardt, Q. B. Chen, Chengbu Liu, Z. H. Li, E. A. Lawrie, Z. Q. Li, C. G. Wu, C. G. Li, C. Y. Niu, S. S. Ntshangase, L. Msebi, Z. Shi, C. G. Wang, D. P. Sun, Robert Bark, X. Wang, Shishu Zhang, Furong Xu, T. R. S. Dinoko, B. V. Kheswa, A. C. Dai, O. Shirinda, and B. H. Sun
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Physics ,Dipole ,Nuclear fusion ,Magnetic dipole ,Chemical reaction ,Molecular physics ,Mechanism (sociology) - Abstract
CITATION: Li, C. G. et al. 2019. “Stapler” mechanism for a dipole band in 79Se. Physical Review C, 100(4). doi:10.1103/PhysRevC.100.044318
- Published
- 2019
28. Corrigendum to 'Two-phonon wobbling in 135Pr' [Phys. Lett. B 792 (2019) 170–174]
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Y. K. Gupta, Q. B. Chen, D. Seweryniak, Wei Li, U. Garg, M. P. Carpenter, R. V. F. Janssens, R. Palit, J. Sethi, T. C. McMaken, S. Frauendorf, G. H. Bhat, N. Sensharma, D. J. Hartley, J. A. Sheikh, F. G. Kondev, K. B. Howard, R. P. Singh, J. L. Cozzi, A. D. Ayangeakaa, S. S. Ghugre, and S. Zhu
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Physics ,Nuclear and High Energy Physics ,Condensed matter physics ,Phonon ,QC1-999 - Published
- 2021
29. Influence of triaxial deformation on wobbling motion in even–even nuclei
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Bin Qi, Q. B. Chen, Hui Zhang, and S. Y. Wang
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Physics ,Nuclear and High Energy Physics ,Angular momentum ,Nuclear Theory ,Deformation (mechanics) ,010308 nuclear & particles physics ,FOS: Physical sciences ,Motion (geometry) ,Harmonic (mathematics) ,Coulomb excitation ,01 natural sciences ,Spectral line ,Nuclear Theory (nucl-th) ,Quantum mechanics ,0103 physical sciences ,Quadrupole ,010306 general physics ,Energy (signal processing) - Abstract
The influence of triaxial deformation γ on the purely collective form of wobbling motion in even–even nuclei is discussed based on the triaxial rotor model. It is found that the harmonic approximation is realized well when the value γ = 30° is adopted for the properties of energy spectra and electric quadrupole transition probabilities, while this approximation gets worse when γ gradually deviates from 30°. Recent data from a Coulomb excitation experiment, namely 3 1 + and 2 2 + for 110Ru, are studied and might be suggested as the bandhead of the wobbling bands. In addition, two types of angular momentum geometries for wobbling motion, stemming from different γ values, are exhibited by the azimuthal plots.
- Published
- 2021
30. Observation of a novel stapler band in 75As
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Q. B. Chen, Jie Meng, Dongxing Jiang, Xun Chen, Q.M. Chen, Shudong Zhang, Furong Xu, W.K. Zhou, J. J. Sun, Xue-Qian Li, Z. H. Li, J. Zhong, Yan-Lin Ye, Cheng Li, Chen-Yang Niu, H. Y. Wu, Yun Zheng, Chengyong Xu, Hui Hua, Cong-Bo Li, Shi-Peng Hu, W.Y. Liang, P. J. Li, Rushan Han, Guangsheng Li, Xiao-Guang Wu, He Chuangye, and Chen-Yu Wang
- Subjects
Physics ,Angular momentum ,Nuclear and High Energy Physics ,Valence (chemistry) ,010308 nuclear & particles physics ,Stapler band ,Tilted axis cranking covariant density functional theory ,01 natural sciences ,lcsh:QC1-999 ,Dipole ,75As ,0103 physical sciences ,Density functional theory ,Neutron ,Covariant transformation ,Atomic physics ,010306 general physics ,Spectroscopy ,Beam energy ,Magnetic rotation ,lcsh:Physics - Abstract
The heavy ion fusion–evaporation reaction study for the high-spin spectroscopy of 75As has been performed via the reaction channel 70Zn(9Be, 1p3n)75As at a beam energy of 42 MeV. The collective structure especially a dipole band in 75As is established for the first time. The properties of this dipole band are investigated in terms of the self-consistent tilted axis cranking covariant density functional theory. Based on the theoretical description and the examination of the angular momentum components, this dipole band can be interpreted as a novel stapler band, where the valence neutrons in ( 1 g 9 / 2 ) orbital rather than the collective core are responsible for the closing of the stapler of angular momentum.
- Published
- 2017
- Full Text
- View/download PDF
31. Structure of odd- A Pt isotopes along the line of stability
- Author
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F. G. Kondev, D. Seweryniak, S. Zhu, C. J. Lister, T. Lauritsen, S. K. Tandel, T. L. Khoo, P. Chowdhury, Q. B. Chen, S. G. Wahid, R. V. F. Janssens, M. P. Carpenter, and Jie Meng
- Subjects
Physics ,Angular momentum ,Isotope ,010308 nuclear & particles physics ,Yrast ,Structure (category theory) ,01 natural sciences ,0103 physical sciences ,Density functional theory ,Neutron ,Atomic physics ,010306 general physics ,Line (formation) ,Spin-½ - Abstract
The structure of the odd-$A$ isotopes $^{193,195,197}\mathrm{Pt}$, which lie along the line of stability, has been studied up to high spin through multinucleon transfer reactions. Positive- and negative-parity sequences in $^{193,195}\mathrm{Pt}$ have been considerably extended and multiple band crossings established. An isomer with ${T}_{1/2}=5.0(5)$ ns and ${I}^{\ensuremath{\pi}}=25/{2}^{\ensuremath{-}}$ is present in $^{195}\mathrm{Pt}$. The isotopes $^{193,195}\mathrm{Pt}$ are characterized by moderate oblate deformation, and angular momentum generation at high spin in the yrast, positive-parity sequences is attributed to the rotation alignment of ${i}_{13/2}$ neutrons and ${h}_{11/2}$ protons. A detailed understanding of the observed features is presented using calculations based on tilted axis cranking covariant density functional theory as well as others with the ultimate cranker code.
- Published
- 2019
32. Microscopic resolution of the nuclear chiral conundrum with crossing twin bands in Ag106
- Author
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Pengwei Zhao, Q. B. Chen, and Y. K. Wang
- Subjects
Physics ,010308 nuclear & particles physics ,Routhian ,Nuclear Theory ,Resolution (electron density) ,01 natural sciences ,Molecular physics ,Spectral line ,0103 physical sciences ,Quasiparticle ,Density functional theory ,Covariant transformation ,010306 general physics ,Nuclear theory ,Solid solution - Abstract
The nuclear chiral conundrum with crossing twin bands is investigated with three-dimensional tilted axis cranking covariant density functional theory in a fully self-consistent and microscopic way. The energy spectra and electromagnetic transition strengths for bands 1 and 2 in Ag-106 are well reproduced with two distinct configurations with two and four quasiparticles, respectively. For the four-quasiparticle configuration, a chiral vibrational band on top of band 2 is expected due to the soft Routhian curves. Therefore, it provides a microscopic and solid solution for the chiral conundrum in Ag-106. It also paves the way for understanding similar chiral structure in other nuclei in the future..
- Published
- 2019
33. Experimental Evidence for Transverse Wobbling in Pd105
- Author
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C. Vaman, P. Bednarczyk, B. Kruzsicz, J. Gizon, K. Starosta, Pankaj S. Joshi, D. Curien, R. Wadsworth, Q. B. Chen, Alejandro Algora, D. G. Jenkins, B. M. Nyakó, A. Gizon, Anthony J. H. Simons, János Timár, István Kuti, Zsolt Dombrádi, Jie Meng, Takeshi Koike, J. N. Scheurer, Shudong Zhang, L. Zolnai, G. Rainovski, A. Krasznahorkay, E. S. Paul, G. Duchêne, Jozsef Molnar, and Dóra Sohler
- Subjects
Physics ,Quantum particle ,Rotor (electric) ,Nuclear Theory ,General Physics and Astronomy ,01 natural sciences ,Molecular physics ,Physics::Geophysics ,law.invention ,Transverse plane ,law ,0103 physical sciences ,Covariant transformation ,Density functional theory ,010306 general physics ,Nuclear theory ,Energy (signal processing) ,Spin-½ - Abstract
New rotational bands built on the ν(h_{11/2}) configuration have been identified in ^{105}Pd. Two bands built on this configuration show the characteristics of transverse wobbling: the ΔI=1 transitions between them have a predominant E2 component and the wobbling energy decreases with increasing spin. The properties of the observed wobbling bands are in good agreement with theoretical results obtained using constrained triaxial covariant density functional theory and quantum particle rotor model calculations. This provides the first experimental evidence for transverse wobbling bands based on a one-neutron configuration, and also represents the first observation of wobbling motion in the A∼100 mass region.
- Published
- 2019
34. Identification of high- K rotation in Ba130 : Testing the consistency of electromagnetic observables
- Author
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Philip M Walker, D. Mengoni, Song Guo, Jianlu Wang, G. Jaworski, Q. B. Chen, D. Bazzacco, István Kuti, Corina Andreoiu, M. Siciliano, D. R. Napoli, A. C. Dai, Furong Xu, T. Marchlewski, A. Astier, X. H. Zhou, C. M. Petrache, K. Whitmore, A. Tucholski, Bo Cederwall, J. J. Valiente-Dobón, K. Ortner, E. Dupont, A. Boso, F. Galtarossa, J. Srebrny, D. Sohler, B. F. Lv, Y. H. Qiang, A. Goasduff, M. L. Liu, E. A. Lawrie, D. A. Testov, F. Recchia, F. H. Garcia, and S. Riccetto
- Subjects
Nuclear physics ,Physics ,Dipole ,010308 nuclear & particles physics ,Consistency (statistics) ,0103 physical sciences ,Neutron ,Observable ,010306 general physics ,Rotation ,01 natural sciences ,Mixing (physics) ,High-κ dielectric - Abstract
The band built on the Kπ = 8−, T1/2 = 9.4 ms isomer of 130Ba has been identified, filling the gap in the systematics of the dipole bands built on the 8− isomers in the N = 74 isotones from 128Xe to 138Gd. The use of the GALILEO array in conjunction with its ancillaries EUCLIDES and Neutron Wall, helped to firmly place the newly identified transitions on top of the long-lived isomer. The extracted gK and gR gyromagnetic factors are in agreement with the 7/2+[404] ⊗ 9/2−[514] two-neutron Nilsson configuration. Particle-rotor model calculations give an understanding of the limited degree of K mixing. The experimental information on the Kπ = 8− isomer of 130Ba is now the most complete among the K isomers of the N = 74 isotones.
- Published
- 2019
35. Transverse wobbling in an even-even nucleus
- Author
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Q. B. Chen, C. M. Petrache, S. Frauendorf, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Physics ,Quantum particle ,Angular momentum ,Nuclear Theory ,[PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th] ,010308 nuclear & particles physics ,Motion (geometry) ,FOS: Physical sciences ,[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] ,Nuclear Structure ,01 natural sciences ,Nuclear Theory (nucl-th) ,Transverse plane ,medicine.anatomical_structure ,0103 physical sciences ,medicine ,Density functional theory ,Covariant transformation ,Atomic physics ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Nucleus ,Nuclear Experiment ,Energy (signal processing) - Abstract
Two new bands built on the two-quasiparticle $\pi(h_{11/2})^2$ configuration of the even-even nucleus $^{130}$Ba are investigated using constrained triaxial covariant density functional theory combined with quantum particle rotor model calculations. The energy difference between the two bands, as well as the available electromagnetic transition probabilities $B(M1)_{\textrm{out}}/B(E2)_{\textrm{in}}$ and $B(E2)_{\textrm{out}}/B(E2)_{\rm{in}}$, are well reproduced. The analysis of the angular momentum geometry reveals that the higher band represents transverse wobbling motion of a two-quasiparticle configuration. This is the first example of two-quasiparticle wobbling bands in an even-even nucleus., Comment: 5 pages, 4 figures
- Published
- 2019
36. Behavior of the collective rotor in nuclear chiral motion
- Author
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Ulf-G. Meißner, Jie Meng, Norbert Kaiser, and Q. B. Chen
- Subjects
Physics ,Angular momentum ,Spins ,Proton ,Nuclear Theory ,010308 nuclear & particles physics ,High Energy Physics::Phenomenology ,FOS: Physical sciences ,Rotation ,01 natural sciences ,Nuclear Theory (nucl-th) ,Quantum mechanics ,0103 physical sciences ,Neutron ,ddc:530 ,010306 general physics ,Energy (signal processing) ,Rotor (mathematics) ,Principal axis theorem - Abstract
The behavior of the collective rotor in the chiral motion of triaxially deformed nuclei is investigated using the particle rotor model by transforming the wave functions from the $K$-representation to the $R$-representation. After examining the energy spectra of the doublet bands and their energy differences as functions of the triaxial deformation, the angular momentum components of the rotor, proton, neutron, and the total system are investigated. Moreover, the probability distributions of the rotor angular momentum ($R$-plots) and their projections onto the three principal axes ($K_R$-plots) are analyzed. The evolution of the chiral mode from a chiral vibration at the low spins to a chiral rotation at high spins is illustrated at triaxial deformations $\gamma=20^\circ$ and $30^\circ$., Comment: 21 pages, 6 figures
- Published
- 2019
- Full Text
- View/download PDF
37. Diversity of shapes and rotations in the $\gamma$-soft $^{130}$Ba nucleus: First observation of a $t$-band in the $A=130$ mass region
- Author
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Song Guo, Miao Liu, B. F. Lv, A. Boso, D. Mengoni, Q. B. Chen, István Kuti, E. A. Lawrie, D. R. Napoli, Corina Andreoiu, K. K. Zheng, Torbjörn Bäck, J. J. Valiente-Dobón, M. Siciliano, K. Ortner, Y. H. Qiang, F. Galtarossa, G. Jaworski, J. Srebrny, S. Frauendorf, S. Riccetto, K. Whitmore, Xiaojuan Zhou, Jie Wang, E. Dupont, D. Bazzacco, T. Marchlewski, F. H. Garcia, D. Testov, Dóra Sohler, A. Astier, Y. X. Liu, János Timár, F. Recchia, A. Tucholski, Philip M Walker, Ramon Wyss, A. Goasduff, Bo Cederwall, C. M. Petrache, R. Li, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay
- Subjects
Nuclear and High Energy Physics ,Projected shell model ,Proton ,Nuclear Theory ,FOS: Physical sciences ,Collective rotations ,Nuclear structure ,Particle rotor model ,Shape coexistence ,Tiltid axis cranking ,[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex] ,Rotation ,01 natural sciences ,Molecular physics ,Nuclear Theory (nucl-th) ,0103 physical sciences ,Neutron ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Nuclear Experiment ,Spin-½ ,Physics ,Spins ,010308 nuclear & particles physics ,lcsh:QC1-999 ,Dipole ,Quasiparticle ,lcsh:Physics - Abstract
Several new bands have been identified in 130Ba, among which there is one with band-head spin 8+. Its properties are in agreement with the Fermi-aligned \nu h11/2^2 , 7/2+[523] \otimes 9/2-[514] Nilsson configuration. This is the first observation of a two-quasiparticle t-band in the A=130 mass region. The t-band is fed by a dipole band involving two additional h11/2 protons. The odd-spin partners of the proton and neutron S-bands and the ground-state band at high spins are also newly identified. The observed bands are discussed using several theoretical models, which strongly suggest the coexistence of prolate and oblate shapes polarized by rotation aligned two-proton and two-neutron configurations, as well as prolate collective rotations around axes with different orientations. With the new results, 130Ba presents one of the best and most complete sets of collective excitations that a gamma-soft nucleus can manifest at medium and high spins, revealing a diversity of shapes and rotations for the nuclei in the A = 130 mass region., Comment: 8 pages, 7 figures
- Published
- 2019
38. Covariant density functional theory for nuclear chirality in 135Nd
- Author
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Q. B. Chen and J. Peng
- Subjects
Physics ,Nuclear and High Energy Physics ,Valence (chemistry) ,Nuclear Theory ,010308 nuclear & particles physics ,FOS: Physical sciences ,01 natural sciences ,lcsh:QC1-999 ,ddc ,Nuclear Theory (nucl-th) ,Planar ,Classical mechanics ,Critical frequency ,Mean field theory ,0103 physical sciences ,Density functional theory ,Covariant transformation ,Nuclear Experiment (nucl-ex) ,Microscopic theory ,010306 general physics ,Chirality (chemistry) ,Nuclear Experiment ,lcsh:Physics - Abstract
The three-dimensional tilted axis cranking covariant density functional theory (3D-TAC CDFT) is used to study the chiral modes in $^{135}$Nd. By modeling the motion of the nucleus in rotating mean field as the interplay between the single-particle motions of several valence particle(s) and hole(s) and the collective motion of a core-like part, a classical Routhian is extracted. This classical Routhian gives qualitative agreement with the 3D-TAC CDFT result for the critical frequency corresponding to the transition from planar to aplanar rotation. Based on this investigation a possible understanding of tilted rotation appearing in a microscopic theory is provided., Comment: 6 pages, 4 figures
- Published
- 2020
39. Triaxiality-related nuclear phenomena in the A ≈ 100 mass region
- Author
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Takeshi Koike, Jozsef Molnar, Q. B. Chen, József Tímár, K. Starosta, B. M. Nyakó, R. Wadsworth, B. Kruzsicz, D. Sohler, Shishu Zhang, Pankaj S. Joshi, István Kuti, and Jie Meng
- Subjects
Physics ,History ,Transverse plane ,Condensed matter physics ,Nuclear Theory ,Motion (geometry) ,Rotation ,Chirality (chemistry) ,Nuclear shape ,Physics::Geophysics ,Computer Science Applications ,Education - Abstract
Solid experimental evidence for triaxial nuclear shape is difficult to obtain and is quite rare. Such evidence can be provided by the phenomena of chiral rotation and wobbling motion, as these can occur only in triaxially deformed nuclei. Although nuclear chirality is well documented in different mass regions, experimental evidence for multiple chiral bands as well as for wobbling motion has been reported so far only in a few nuclei. Pd and Rh nuclei in the A ≈ 100 mass region have been recently studied, and transverse wobbling motion as well as multiple chiral band structures were identified for the first time in this region. These observations provide experimental evidence for the predicted triaxial shape in this mass region, and new data which enable a better understanding of the studied phenomena.
- Published
- 2020
40. Exploring nuclear multiple chirality in the A≈60 mass region within covariant density functional theory
- Author
-
J. Peng and Q. B. Chen
- Subjects
Physics ,Nuclear Theory ,Isotope ,010308 nuclear & particles physics ,FOS: Physical sciences ,Approx ,01 natural sciences ,Nuclear Theory (nucl-th) ,0103 physical sciences ,Covariant transformation ,Beta (velocity) ,Density functional theory ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Adiabatic process ,Chirality (chemistry) ,Nuclear Experiment ,Nuclear theory ,Mathematical physics - Abstract
The nuclear multiple chirality in $A\sim60$ mass region is explored by the adiabatic and configuration-fixed constrained covariant density functional theory for cobalt isotopes. The potential-energy curves and triaxiality parameters $\gamma$ as functions of the deformation parameter $\beta$ in $^{54,56,57,58,59,60}$Co are obtained. It is found that there are high-$j$ particle(s) and hole(s) configurations with prominent triaxially deformed shapes in these isotopes. This points towards that the existence of chirality or multiple chirality in $A\sim60$ mass region are highly anticipated., Comment: 13 pages, 5 figures, 1 table, accepted by Phys. Rev. C
- Published
- 2018
41. [Improving the methods for processing specimens derived from endobronchial ultrasound-guided transbronchial needle aspiration so as to increase the pathological diagnosis accuracy]
- Author
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Q R, Chen, F, Yang, X, Feng, M X, Wang, S, Jin, M W, Wang, D, Wu, Y G L, Zhang, Y M, Wu, H B, Wang, and Q B, Chen
- Published
- 2018
42. Reexamine the nuclear chiral geometry from the orientation of the angular momentum
- Author
-
Q. B. Chen and Jie Meng
- Subjects
Physics ,Angular momentum ,Nuclear Theory ,010308 nuclear & particles physics ,FOS: Physical sciences ,Geometry ,01 natural sciences ,Nuclear Theory (nucl-th) ,Orientation (geometry) ,0103 physical sciences ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Nuclear Experiment ,Nuclear theory - Abstract
The paradox on the previous interpretation for the nuclear chiral geometry based on the effective angle has been clarified by reexamining the system with the particle-hole configuration $\pi (1h_{11/2})^1 \otimes \nu(1h_{11/2})^{-1}$ and rotor with deformation parameter $\gamma=30^\circ$. It is found that the paradox is caused by the fact that the angular momentum of the rotor is much smaller than those of the proton and the neutron near the bandhead. Hence, it does not support a chiral rotation interpretation near the bandhead. The nuclear chiral geometry based on the effective angle makes sense only when the angular momentum of the rotor becomes comparable with those of the proton and the neutron at the certain spin region., Comment: 14 pages, 4 figures
- Published
- 2018
43. Three-level mixing model for nuclear chiral rotation: Role of planar component
- Author
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Takeshi Koike, Q. B. Chen, and K. Starosta
- Subjects
Physics ,Valence (chemistry) ,Hamiltonian matrix ,Proton ,Nuclear Theory ,010308 nuclear & particles physics ,High Energy Physics::Phenomenology ,FOS: Physical sciences ,Eigenfunction ,01 natural sciences ,Nuclear Theory (nucl-th) ,Mean field theory ,0103 physical sciences ,Atomic nucleus ,Quadrupole ,Nuclear Experiment (nucl-ex) ,Atomic physics ,010306 general physics ,Nucleon ,Nuclear Experiment - Abstract
Three- and two-level mixing models are proposed to understand the doubling of states at the same spin and parity in triaxially-deformed atomic nuclei with odd numbers of protons and neutrons. The Particle-Rotor Model for such nuclei is solved using the newly proposed basis which couples angular momenta of two valence nucleons and the rotating triaxial mean-field into left-handed $|\mathcal{L}\rangle$, right-handed $|\mathcal{R}\rangle$, and planar $|\mathcal{P}\rangle$ configurations. The presence and the impact of the planar component is investigated as a function of the total spin for mass A$\approx$130 nuclei with the valence h$_{11/2}$ proton particle, valence h$_{11/2}$ neutron hole and the maximum difference between principle axes allowed by the quadrupole deformation of the mean field. It is concluded that at each spin value the higher-energy member of a doublet of states is built on the anti-symmetric combination of $|\mathcal{L}\rangle$ and $|\mathcal{R}\rangle$ and is free of the $|\mathcal{P}\rangle$ component, indicating that it is of pure chiral geometry. For the lower-energy member of the doublet, the contribution of the $|\mathcal{P}\rangle$ component to the eigenfunction first decreases and then increases as a function of the total spin. This trend as well as the energy splitting between the doublet states are both determined by the Hamiltonian matrix elements between the planar ($|\mathcal{P}\rangle$) and non-planar ($|\mathcal{L}\rangle$ and $|\mathcal{R}\rangle$) subspaces of the full Hilbert space., 12 pages, 5 figures, accepted as a Rapid Communication in Physical Review C
- Published
- 2018
44. Low-lying states in even Gd isotopes studied with five-dimensional collective Hamiltonian based on covariant density functional theory
- Author
-
Q. B. Chen, Shishu Zhang, and Z. Shi
- Subjects
Physics ,Nuclear and High Energy Physics ,Nuclear Theory ,010308 nuclear & particles physics ,Hadron ,FOS: Physical sciences ,01 natural sciences ,Spectral line ,Nuclear Theory (nucl-th) ,symbols.namesake ,Quantum mechanics ,0103 physical sciences ,symbols ,Nuclear fusion ,Density functional theory ,Neutron ,Covariant transformation ,Interacting boson model ,010306 general physics ,Hamiltonian (quantum mechanics) - Abstract
Five-dimensional collective Hamiltonian based on the covariant density functional theory has been applied to study the the low-lying states of even-even $^{148-162}$Gd isotopes. The shape evolution from $^{148}$Gd to $^{162}$Gd is presented. The experimental energy spectra and intraband $B(E2)$ transition probabilities for the $^{148-162}$Gd isotopes are reproduced by the present calculations. The relative $B(E2)$ ratios in present calculations are also compared with the available interacting boson model results and experimental data. It is found that the occupations of neutron $1i_{13/2}$ orbital result in the well-deformed prolate shape, and are essential for Gd isotopes., 11pages, 10figures
- Published
- 2018
45. Shell-model-like approach based on cranking covariant density functional theory: Band crossing and shape evolution in Fe60
- Author
-
Shishu Zhang, Q. B. Chen, Zhenwei Shi, Zhen-Hua Zhang, and Jie Meng
- Subjects
Physics ,Angular momentum ,010308 nuclear & particles physics ,01 natural sciences ,Spectral line ,symbols.namesake ,Atomic orbital ,Pairing ,0103 physical sciences ,symbols ,Covariant transformation ,Neutron ,Density functional theory ,Atomic physics ,010306 general physics ,Hamiltonian (quantum mechanics) - Abstract
The shell-model-like approach is implemented to treat the cranking many-body Hamiltonian based on the covariant density functional theory including pairing correlations with exact particle number conservation. The self-consistency is achieved by iterating the single-particle occupation probabilities back to the densities and currents. As an example, the rotational structures observed in the neutron-rich nucleus $^{60}\mathrm{Fe}$ are investigated and analyzed. Without introducing any ad hoc parameters, the bandheads, the rotational spectra, and the relations between the angular momentum and rotational frequency for the positive-parity band A and negative-parity bands B and C are well reproduced. The essential role of the pairing correlations is revealed. It is found that for band A, the band crossing is due to the change of the last two occupied neutrons from the $1{f}_{5/2}$ signature partners to the $1{g}_{9/2}$ signature partners. For the two negative-parity signature partner bands B and C, the band crossings are due to the pseudocrossing between the $1{f}_{7/2,5/2}$ and the $1{f}_{5/2,1/2}$ orbitals. Generally speaking, the deformation parameters $\ensuremath{\beta}$ for bands A, B, and C decrease with rotational frequency. For band A, the deformation jumps from $\ensuremath{\beta}\ensuremath{\approx}0.19$ to $\ensuremath{\beta}\ensuremath{\approx}0.29$ around the band crossing. In comparison with its signature partner band C, band B exhibits appreciable triaxial deformation.
- Published
- 2018
46. First Measurement of the g Factor in the Chiral Band: The Case of the Cs128 Isomeric State
- Author
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Q. B. Chen, Stanisław G. Rohoziński, E. Fiori, Tan Ahn, Jie Meng, L. Próchniak, M. Zielinska, M. Ionescu-Bujor, R. Lozeva, K. Starosta, Ch. Droste, Shudong Zhang, T. Marchlewski, F. Recchia, Lu Yu, E. Grodner, M. Kisieliński, J. Srebrny, S. Aydin, M. Kowalczyk, C. A. Ur, Pengwei Zhao, and Georgi Georgiev
- Subjects
Physics ,Angular momentum ,Proton ,010308 nuclear & particles physics ,Plane (geometry) ,General Physics and Astronomy ,State (functional analysis) ,Rotation ,01 natural sciences ,Orientation (vector space) ,Total angular momentum quantum number ,0103 physical sciences ,Neutron ,Atomic physics ,010306 general physics - Abstract
The $g$ factor of the 56 ns half-life isomeric state in $^{128}\mathrm{Cs}$ has been measured using the time-differential perturbed angular distribution method. This state is the bandhead of the positive-parity chiral rotational band, which emerges when an unpaired proton, an unpaired neutron hole, and an even-even core are coupled such that their angular momentum vectors are aplanar (chiral configuration). $g$-factor measurements can give important information on the relative orientation of the three angular momentum vectors. The measured $g$ factor $g=+0.59(1)$ shows that there is an important contribution of the core rotation in the total angular momentum of the isomeric state. Moreover, a quantitative theoretical analysis supports the conclusion that the three angular momentum vectors lie almost in one plane, which suggests that the chiral configuration in $^{128}\mathrm{Cs}$ demonstrated in previous works by characteristic patterns of electromagnetic transitions appears only above some value of the total nuclear spin.
- Published
- 2018
47. Effective field theory for collective rotations and vibrations of triaxially deformed nuclei
- Author
-
Ulf-G. Meißner, Jie Meng, Q. B. Chen, and Norbert Kaiser
- Subjects
Physics ,Nuclear Theory ,010308 nuclear & particles physics ,FOS: Physical sciences ,01 natural sciences ,Vibration ,Nuclear Theory (nucl-th) ,symbols.namesake ,Classical mechanics ,0103 physical sciences ,Effective field theory ,symbols ,ddc:530 ,010306 general physics ,Hamiltonian (quantum mechanics) ,Nuclear theory - Abstract
The effective field theory (EFT) for triaxially deformed even-even nuclei is generalized to include the vibrational degrees of freedom. The pertinent Hamiltonian is constructed up to next-to-leading order. The leading order part describes the vibrational motion, and the NLO part couples rotations to vibrations. The applicability of the EFT Hamiltonian is examined through the description of the energy spectra of the ground state bands, $\gamma$-bands, and $K=4$ bands in the $^{108, 110, 112}$Ru isotopes. It is found that by taking into account the vibrational degrees of freedom, the deviations for high-spin states in the $\gamma$-band observed in the EFT with only rotational degrees of freedom disappear. This supports the importance of including vibrational degrees of freedom in the EFT formulation for the collective motion of triaxially deformed nuclei., Comment: 23 pages, 3 figures, 1 table
- Published
- 2018
- Full Text
- View/download PDF
48. Two-dimensional collective Hamiltonian for chiral and wobbling modes II: Electromagnetic transitions
- Author
-
Jie Meng, Pengwei Zhao, Xuhao Wu, Q. B. Chen, and Shishu Zhang
- Subjects
Physics ,Nuclear Theory ,010308 nuclear & particles physics ,Yrast ,FOS: Physical sciences ,01 natural sciences ,Nuclear Theory (nucl-th) ,symbols.namesake ,Quantum mechanics ,0103 physical sciences ,symbols ,Neutron ,Rotational axis ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Hamiltonian (quantum mechanics) ,Nuclear theory ,Nuclear Experiment ,Quantum fluctuation ,Excitation - Abstract
The intraband electromagnetic transitions in the framework of collective Hamiltonian for chiral and wobbling modes are calculated. By going beyond the mean field approximation on the orientations of rotational axis, the collective Hamiltonian provides the descriptions on both yrast band and collective excitation bands. For a system with one $h_{11/2}$ proton particle and one $h_{11/2}$ neutron hole coupled to a triaxial rotor ($\gamma=-30^\circ$), the intraband electromagnetic transitions given by the one-dimensional and two-dimensional collective Hamiltonian are compared to the results by the tilted axis cranking approach and particle rotor model. Compared with the tilted axis cranking approach, the electromagnetic transitions given by the collective Hamiltonian have a better agreement with those by the particle rotor model, due to the consideration of the quantum fluctuations., Comment: 17 pages, 4 figures
- Published
- 2018
- Full Text
- View/download PDF
49. Behavior of the collective rotor in wobbling motion
- Author
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Ulf-G. Meißner, E. Streck, Norbert Kaiser, and Q. B. Chen
- Subjects
Physics ,Angular momentum ,Spins ,Nuclear Theory ,010308 nuclear & particles physics ,Rotor (electric) ,FOS: Physical sciences ,Coupling (probability) ,01 natural sciences ,law.invention ,Nuclear Theory (nucl-th) ,Transverse plane ,Total angular momentum quantum number ,law ,Quantum mechanics ,0103 physical sciences ,ddc:530 ,Nuclear Experiment (nucl-ex) ,010306 general physics ,Nuclear Experiment ,Energy (signal processing) ,Principal axis theorem - Abstract
The behavior of the collective rotor in wobbling motion is investigated within the particle-rotor model for the nucleus $^{135}$Pr by transforming the wave functions from the $K$-representation to the $R$-representation. After reproducing the experimental energy spectra and wobbling frequencies, the evolution of the wobbling mode in $^{135}$Pr, from transverse at low spins to longitudinal at high spins, is illustrated by the distributions of the total angular momentum in the intrinsic reference frame (azimuthal plot). Finally, the coupling schemes of the angular momenta of the rotor and the high-$j$ particle for transverse and longitudinal wobbling are obtained from the analysis of the probability distributions of the rotor angular momentum ($R$-plots) and their projections onto the three principal axes ($K_R$-plots)., Comment: 21 pages, 9 pages
- Published
- 2018
- Full Text
- View/download PDF
50. β-decay study of neutron-rich nucleus 34Al
- Author
-
Jian-Song Wang, Chao He, Hui Hua, Yong Li, Dongxing Jiang, Wei Jiang, Chen-Guang Li, H. Y. Wu, Yuhu Zhang, Xiaochi Chen, Wei-Hu Ma, Q. B. Chen, Jie Meng, Wenlong Zhan, Peng Ma, Guoqing Xiao, Y.L. Sun, Rui Han, H. L. Zang, Xiangqing Li, Sidong Chen, Qiang Liu, Zhihuan Li, P. J. Li, Cenxi Yuan, Yan-Yun Yang, Shuangquan Zhang, Shi-Lun Jin, Chun-Guang Wang, Yuanjie Zhou, Mei-Rong Huang, J. B. Ma, Chen-Yang Niu, Hu Zhengguo, Jing Li, Furong Xu, Zhen Bai, Jun Feng, Z. Li, Chuan Xu, Xiao-Hong Zhou, Yan-Lin Ye, Hu-Shan Xu, and WeiGuang Jiang
- Subjects
Nuclear physics ,Physics ,medicine.anatomical_structure ,010308 nuclear & particles physics ,0103 physical sciences ,medicine ,General Physics and Astronomy ,Neutron ,010306 general physics ,01 natural sciences ,Nucleus - Published
- 2017
Catalog
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