中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Search for in-band transitions in the candidate superdeformed band in Si-28

文献类型:期刊论文

作者Morris, L.11; Jenkins, D. G.11,12; Harakeh, M. N.13,14; Isaak, J.13,15; Kobayashi, N.13; Tamii, A.13; Adachi, S.13; Adsley, P.16; Aoi, N.13; Bracco, A.17,18
刊名PHYSICAL REVIEW C
出版日期2021-11-30
卷号104期号:5页码:8
ISSN号2469-9985
DOI10.1103/PhysRevC.104.054323
通讯作者Jenkins, D. G.(david.jenkins@york.ac.uk)
英文摘要Background: Superdeformed (SD) bands are suggested by theory around Ca-40 and in lighter alpha-conjugate nuclei such as Mg-24, Si-28, and S-32. Such predictions originate from a number of theoretical models including mean-field models and antisymmetrized molecular dynamics (AMD) calculations. While SD bands have been identified in Ca-40 and its near neighbors, evidence of their existence in the lighter, midshell nuclei is circumstantial at best. The key evidence of superdeformation would be the observation of transitions with high B(E2) transition strengths connecting states in a rotational sequence. This is challenging information to obtain since the bands lie at a high excitation energy and competition from out-of-band decay is dominant. Purpose: The purpose of the present study is to establish a new methodology to circumvent the difficulties in identifying and quantifying in-band transitions through directly populating candidate states in the SD band in Si-28 through inelastic alpha scattering, selecting such states with a spectrometer, and measuring their gamma-ray decay with a large array of high-purity germanium detectors, allowing direct access to electromagnetic transition strengths. Methods: Excited states in Si-28 were populated in the Si-28(alpha, alpha') reaction using a 130-MeV He-4 beam from the K140 AVF cyclotron at the Research Center for Nuclear Physics. Outgoing alpha particles were analyzed using the Grand Raiden spectrometer positioned at an angle of 9.1 degrees to favor the population of states with J approximate to 4. Coincident gamma rays were detected with the CAGRA array of 12 HPGe clover detectors augmented by a set of four large LaBr3 detectors. Results: Data analysis showed that it was possible to identify additional low-energy transitions in competition with high-energy decays from excited states in Si-28 in the vicinity of 10 MeV. However, while the candidate 4(+) SD state at 10.944 MeV was populated, a 1148-keV transition to the candidate 2(+) SD state at 9.796 MeV was not observed, and only an upper limit for its transition strength of B(E2) < 43 W.u. could be established. This contradicts AMD predictions of approximate to 200 W.u. for such a transition. Conclusion: The present study strongly rejects the hypothesis that the candidate set of states identified in 28 Si represents an SD band, which demonstrates the potential of the methodology devised here.
WOS关键词NUCLEUS
资助项目International Joint Research Promotion Program of Osaka University ; Deutsche Forschungsgemeinschaft (DFG)[SFB 1245] ; Deutsche Forschungsgemeinschaft (DFG)[279384907]
WOS研究方向Physics
语种英语
WOS记录号WOS:000725661600002
出版者AMER PHYSICAL SOC
资助机构International Joint Research Promotion Program of Osaka University ; Deutsche Forschungsgemeinschaft (DFG)
源URL[http://119.78.100.186/handle/113462/140052]  
专题中国科学院近代物理研究所
通讯作者Jenkins, D. G.
作者单位1.PAN, Inst Nucl Phys, PL-31342 Krakow, Poland
2.Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA
3.Univ Cologne, Inst Nucl Phys, D-50937 Cologne, Germany
4.GSI Helmholtzzentrum Schwerionenforsch GmbH, D-64291 Darmstadt, Germany
5.Argonne Natl Lab, Phys Div, 9700 S Cass Ave, Argonne, IL 60439 USA
6.Army Res Lab, DEVCOM, Adelphi, MD 20783 USA
7.Univ Strasbourg, IPHC, F-67037 Strasbourg, France
8.Tohoku Univ, Dept Phys, Sendai, Miyagi 9808578, Japan
9.Univ Tokyo, Ctr Nucl Study CNS, Bunkyo Ku, Tokyo 1130033, Japan
10.Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Peoples R China
推荐引用方式
GB/T 7714
Morris, L.,Jenkins, D. G.,Harakeh, M. N.,et al. Search for in-band transitions in the candidate superdeformed band in Si-28[J]. PHYSICAL REVIEW C,2021,104(5):8.
APA Morris, L..,Jenkins, D. G..,Harakeh, M. N..,Isaak, J..,Kobayashi, N..,...&Zhu, S..(2021).Search for in-band transitions in the candidate superdeformed band in Si-28.PHYSICAL REVIEW C,104(5),8.
MLA Morris, L.,et al."Search for in-band transitions in the candidate superdeformed band in Si-28".PHYSICAL REVIEW C 104.5(2021):8.

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来源:近代物理研究所

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