1
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Liu Y, Ye YL, Lou JL, Yang XF, Baba T, Kimura M, Yang B, Li ZH, Li QT, Xu JY, Ge YC, Hua H, Wang JS, Yang YY, Ma P, Bai Z, Hu Q, Liu W, Ma K, Tao LC, Jiang Y, Hu LY, Zang HL, Feng J, Wu HY, Han JX, Bai SW, Li G, Yu HZ, Huang SW, Chen ZQ, Sun XH, Li JJ, Tan ZW, Gao ZH, Duan FF, Tan JH, Sun SQ, Song YS. Positive-Parity Linear-Chain Molecular Band in ^{16}C. PHYSICAL REVIEW LETTERS 2020; 124:192501. [PMID: 32469564 DOI: 10.1103/physrevlett.124.192501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/31/2020] [Accepted: 04/22/2020] [Indexed: 06/11/2023]
Abstract
An inelastic excitation and cluster-decay experiment ^{2}H(^{16}C,^{4}He+^{12}Be or ^{6}He+^{10}Be)^{2}H was carried out to investigate the linear-chain clustering structure in neutron-rich ^{16}C. For the first time, decay paths from the ^{16}C resonances to various states of the final nuclei were determined, thanks to the well-resolved Q-value spectra obtained from the threefold coincident measurement. The close-threshold resonance at 16.5 MeV is assigned as the J^{π}=0^{+} band head of the predicted positive-parity linear-chain molecular band with (3/2_{π}^{-})^{2}(1/2_{σ}^{-})^{2} configuration, according to the associated angular correlation and decay analysis. Other members of this band were found at 17.3, 19.4, and 21.6 MeV based on their selective decay properties, being consistent with the theoretical predictions. Another intriguing high-lying state was observed at 27.2 MeV which decays almost exclusively to ^{6}He+^{10}Be(∼6 MeV) final channel, corresponding well to another predicted linear-chain structure with the pure σ-bond configuration.
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Affiliation(s)
- Y Liu
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - Y L Ye
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - J L Lou
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - X F Yang
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - T Baba
- Kitami Institute of Technology, 090-8507 Kitami, Japan
| | - M Kimura
- Department of Physics, Hokkaido University, 060-0810 Sapporo, Japan
| | - B Yang
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - Z H Li
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - Q T Li
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - J Y Xu
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - Y C Ge
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - H Hua
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - J S Wang
- School of Science, Huzhou University, Huzhou 313000, China
- Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000, China
| | - Y Y Yang
- Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000, China
| | - P Ma
- Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000, China
| | - Z Bai
- Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000, China
| | - Q Hu
- Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000, China
| | - W Liu
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - K Ma
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - L C Tao
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - Y Jiang
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - L Y Hu
- Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin 150001, China
| | - H L Zang
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - J Feng
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - H Y Wu
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - J X Han
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - S W Bai
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - G Li
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - H Z Yu
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - S W Huang
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - Z Q Chen
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - X H Sun
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - J J Li
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - Z W Tan
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
| | - Z H Gao
- Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000, China
| | - F F Duan
- Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000, China
| | - J H Tan
- Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin 150001, China
| | - S Q Sun
- Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin 150001, China
| | - Y S Song
- Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin 150001, China
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2
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Zhao PW, Itagaki N, Meng J. Rod-shaped Nuclei at Extreme Spin and Isospin. PHYSICAL REVIEW LETTERS 2015; 115:022501. [PMID: 26207464 DOI: 10.1103/physrevlett.115.022501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Indexed: 05/28/2023]
Abstract
The anomalous rod shape in carbon isotopes has been investigated in the framework of the cranking covariant density functional theory, and two mechanisms to stabilize such a novel shape with respect to the bending motion, extreme spin, and isospin are simultaneously discussed for the first time in a self-consistent and microscopic way. By adding valence neutrons and rotating the system, we have found the mechanism stabilizing the rod shape; i.e., the σ orbitals (parallel to the symmetry axis) of the valence neutrons, important for the rod shape, are lowered by the rotation due to the Coriolis term. The spin and isospin effects enhance the stability of the rod-shaped configuration. This provides a strong hint that a rod shape could be realized in nuclei towards extreme spin and isospin.
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Affiliation(s)
- P W Zhao
- Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - N Itagaki
- Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan
| | - J Meng
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
- School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191, China
- Department of Physics, University of Stellenbosch, Stellenbosch 7602, South Africa
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3
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Ito M, Ikeda K. Unified studies of chemical bonding structures and resonant scattering in light neutron-excess systems, 10,12Be. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2014; 77:096301. [PMID: 25222183 DOI: 10.1088/0034-4885/77/9/096301] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The generalized two-center cluster model (GTCM), which can treat covalent, ionic and atomic configurations in general systems with two inert cores plus valence nucleons, is formulated in the basis of the microscopic cluster model. In this model, the covalent configurations constructed by the molecular orbital (MO) method and the atomic (or ionic) configuration obtained by the valence bonding (VB) method can be handled in a consistent manner. The GTCM is applied to the light neutron-rich system (10,12)Be = α + α + Xn (X = 2, 4). The continuous and smooth changes of the neutron orbits from the covalent MO states to the ionic VB states are clearly observed in the adiabatic energy surfaces (AESs), which are the energy curves obtained with a variation of the α-α distance. The energy levels obtained from the AESs nicely reproduce the recent observations over a wide energy region. The individual spectra are characterized in terms of chemical-bonding-like structures, such as the covalent MO or ionic VB structures, according to analysis of their intrinsic wave functions. From the analysis of AESs, the formation of the mysterious 0(2)(+) states in (10,12)Be, which have anomalously small excitation energies in comparison to a naive shell-model prediction, is investigated. A large enhancement in a monopole transition from a ground MO state to an ionic α + (6,8)He VB state is found, which seems to be consistent with a recent observation. In the unbound region, the structure problem, which handles the total system of α + α + Xn (X = 2, 4) as a bound or quasi-bound state, and the reaction problem, induced by the collision of an asymptotic VB state of α + (6,8)He, are combined by the GTCM. The properties of unbound resonant states are discussed in close connection to the reaction mechanism, and some enhancement factors originating from the properties of the intrinsic states are predicted in the reaction observables.
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Affiliation(s)
- Makoto Ito
- Department of Pure and Applied Physics, Kansai University, Yamatecho, 3-3-35, Suita, Japan. Research Center for Nuclear Physics (RCNP), Osaka University, Mihogaoka 10-1, Suita 567-0047, Japan. RIKEN Nishina Center for Accelerator-based Science, RIKEN, Wako,351-0198, Saitama, Japan
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Ichikawa T, Maruhn JA, Itagaki N, Ohkubo S. Linear chain structure of four-α clusters in 16O. PHYSICAL REVIEW LETTERS 2011; 107:112501. [PMID: 22026658 DOI: 10.1103/physrevlett.107.112501] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Indexed: 05/31/2023]
Abstract
We investigate the linear chain configurations of four-α clusters in 16O using a Skyrme cranked Hartree-Fock method and discuss the relationship between the stability of such states and angular momentum. We show the existence of a region of angular momentum (13-18ℏ) where the linear chain configuration is stabilized. For the first time we demonstrate that stable exotic states with a large moment of inertia (ℏ2/2Θ∼0.06-0.08 MeV) can exist.
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Affiliation(s)
- T Ichikawa
- Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan
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5
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Umar AS, Maruhn JA, Itagaki N, Oberacker VE. Microscopic study of the triple-α reaction. PHYSICAL REVIEW LETTERS 2010; 104:212503. [PMID: 20867090 DOI: 10.1103/physrevlett.104.212503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Indexed: 05/29/2023]
Abstract
We present a microscopic dynamical study of the reactions involving three 4He clusters. We show that the much discussed triple-α linear chain configuration of 12C is formed with a certain lifetime and subsequently makes a transition to a triangular configuration of 12C and then to a configuration near the ground state. Time-dependent Hartree-Fock theory coupled with a density constraint is used to study the properties of these configurations.
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Affiliation(s)
- A S Umar
- Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA
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6
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7
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Kun SY. The "shape eigenstate" is the short-lived "macroscopic" molecule. PHYSICAL REVIEW LETTERS 2000; 84:1055. [PMID: 11017439 DOI: 10.1103/physrevlett.84.1055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/1999] [Indexed: 05/23/2023]
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8
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Catford WN. Clustering in Nuclei from N/Z=1 to N/Z=2. THE NUCLEUS 2000. [DOI: 10.1007/978-1-4615-4257-5_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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9
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Wuosmaa AH, Back BB, Betts RR, Freer M, Glagola BG, Henderson DJ, Hofman DJ, Nanal V. Resonance spin assignments in 12C+12C(3(-)) inelastic scattering from angular correlation methods. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1996; 54:2463-2468. [PMID: 9971602 DOI: 10.1103/physrevc.54.2463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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10
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Chappell SP, Rae WD. Angular correlations for alpha -particle decay in the reaction 12C. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1996; 53:2879-2884. [PMID: 9971274 DOI: 10.1103/physrevc.53.2879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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11
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Larochelle Y, Beaulieu L, Anctil G, Djerroud B, Doré D, Laforest R, Pouliot J, Roy R, Samri M, St-Pierre C, Ball GC, Bowman DR, Galindo-Uribarri A, Hagberg E, Horn D, Guinet D, Lautesse P. Dependence of intermediate mass fragment production on the reaction mechanism in light heavy-ion collisions at intermediate energy. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1996; 53:823-837. [PMID: 9971002 DOI: 10.1103/physrevc.53.823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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12
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Freeman RM, Haas F, Elanique A, Morsad A, Beck C. Ec.m.=32.5 MeV resonance in 12C+12C. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1995; 51:3504-3506. [PMID: 9970460 DOI: 10.1103/physrevc.51.3504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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13
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Simmons PM, Rae WD, Chappell SP, Fox SP, Jones CD, Watson DL, Freer M, Fulton BR, Clarke NM, Curtis N, Leddy MJ, Pople JS, Hall SJ, Ward RP, Tungate G, Catford WN, Gyapong GJ, Singer SM, Regan PH. Search for a 7- alpha chain state. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1995; 51:3500-3503. [PMID: 9970459 DOI: 10.1103/physrevc.51.3500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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14
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Hirabayashi Y, Sakuragi Y, Abe Y. 3 alpha +3 alpha and 3 alpha +12C configurations in 24Mg. PHYSICAL REVIEW LETTERS 1995; 74:4141-4144. [PMID: 10058426 DOI: 10.1103/physrevlett.74.4141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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15
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Rae WD, Merchant AC. Schematic model of a 6- alpha chain state. PHYSICAL REVIEW LETTERS 1995; 74:4145-4148. [PMID: 10058427 DOI: 10.1103/physrevlett.74.4145] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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16
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Chappell SP, Watson DL, Fox SP, Jones CD, Rae WD, Simmons PM, Freer M, Fulton BR, Clarke NM, Curtis N, Leddy MJ, Pople JS, Hall SJ, Ward RP, Tungate G, Catford WN, Gyapong GJ, Singer SM, Regan PH. 12C+12C "6 alpha -chain state" resonance. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1995; 51:695-700. [PMID: 9970115 DOI: 10.1103/physrevc.51.695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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17
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Wuosmaa AH, Freer M, Back BB, Betts RR, Gehring JC, Glagola BG, Happ T, Henderson DJ, Wilt P, Bearden IG. Angular-distribution measurements for 12C(12C,12C. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1994; 50:2909-2916. [PMID: 9969991 DOI: 10.1103/physrevc.50.2909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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18
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Liendo JA, Fletcher NR, Caussyn DD, Kemper KW, Towers EE. 15N cluster states in triton transfer and their alpha decay. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1994; 50:3155-3158. [PMID: 9970020 DOI: 10.1103/physrevc.50.3155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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19
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Beck C, Abe Y, Aissaoui N, Djerroud B, Haas F. Role of the number of open channels in the dynamics of the dinucleus binary decay. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1994; 49:2618-2629. [PMID: 9969511 DOI: 10.1103/physrevc.49.2618] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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20
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Rae WD, Merchant AC, Buck B. The shape eigenstate: A new kind of resonance. PHYSICAL REVIEW LETTERS 1992; 69:3709-3712. [PMID: 10046893 DOI: 10.1103/physrevlett.69.3709] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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21
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Merchant AC, Rae WD. Alpha-chain states in 4N-nuclei from 20Ne to 32S. PHYSICAL REVIEW. C, NUCLEAR PHYSICS 1992; 46:2096-2097. [PMID: 9968331 DOI: 10.1103/physrevc.46.2096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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22
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Pauling L. Analysis of gamma-ray energies for 56 excited superdeformed rotational bands of nuclei of lanthanons La to Dy and of Hg, Tl, and Pb on the basis of the two-revolving-cluster model, with evaluation of moments of inertia and radii of revolution and assignment of nucleonic compositions to the clusters and the central sphere. Proc Natl Acad Sci U S A 1992; 89:7277-81. [PMID: 11607313 PMCID: PMC49689 DOI: 10.1073/pnas.89.15.7277] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Analysis of the gamma-ray energies of 28 excited superdeformed bands of lanthanon nuclei by application of the two-revolving-cluster model yields the result that the central sphere for all 28 has the semimagic-magic composition p40n50, with the range p8n12 to p14n18 for the clusters and the radius of revolution increasing from 7.31 to 7.76 fm. Similar analysis of 28 excited bands of Hg, Tl, and Pb nuclei leads to p56n82 (semimagic-magic) for the central sphere of 24 bands, p64n82 (semimagic-magic) for 2, and p64n90 (doubly semimagic) for 2, with cluster range p8n12 to p14n16 and values of the radius of revolution from 8.70 to 8.92 fm for 26 bands and 9.2 fm for 2.
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Affiliation(s)
- L Pauling
- Linus Pauling Institute of Science and Medicine, Palo Alto, CA 94306-2025, USA
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