Studies of pear-shaped nuclei using accelerated radioactive beams

被引：297

作者：

Gaffney, L. P. ^{[1
]}

Butler, P. A. ^{[1
]}

Scheck, M. ^{[1
,2
]}

Hayes, A. B. ^{[3
]}

Wenander, F. ^{[4
]}

Albers, M. ^{[5
]}

Bastin, B. ^{[6
]}

Bauer, C. ^{[2
]}

Blazhev, A. ^{[5
]}

Boenig, S. ^{[2
]}

Bree, N. ^{[7
]}

Cederkall, J. ^{[8
]}

Chupp, T. ^{[9
]}

Cline, D. ^{[3
]}

Cocolios, T. E. ^{[4
]}

Davinson, T. ^{[10
]}

DeWitte, H. ^{[7
]}

Diriken, J. ^{[7
,11
]}

Grahn, T. ^{[12
,13
]}

Herzan, A. ^{[12
,13
]}

Huyse, M. ^{[7
]}

Jenkins, D. G. ^{[14
]}

Joss, D. T. ^{[1
]}

Kesteloot, N. ^{[7
,11
]}

Konki, J. ^{[12
,13
]}

Kowalczyk, M. ^{[15
]}

Kroell, Th. ^{[2
]}

Kwan, E. ^{[16
]}

Lutter, R. ^{[17
,18
]}

Moschner, K. ^{[5
]}

Napiorkowski, P. ^{[15
]}

Pakarinen, J. ^{[4
,12
,13
]}

Pfeiffer, M. ^{[5
]}

Radeck, D. ^{[5
]}

Reiter, P. ^{[5
]}

Reynders, K. ^{[7
]}

Rigby, S. V. ^{[1
]}

Robledo, L. M. ^{[19
]}

Rudigier, M. ^{[5
]}

Sambi, S. ^{[7
]}

Seidlitz, M. ^{[5
]}

Siebeck, B. ^{[5
]}

Stora, T. ^{[4
]}

Thoele, P. ^{[5
]}

Van Duppen, P. ^{[7
]}

Vermeulen, M. J. ^{[14
]}

von Schmid, M. ^{[2
]}

Voulot, D. ^{[4
]}

Warr, N. ^{[5
]}

Wimmer, K. ^{[20
]}

机构：

[1] Univ Liverpool, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England

[2] Tech Univ Darmstadt, Inst Kernphys, D-64289 Darmstadt, Germany

[3] Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA

[4] CERN Org Europeenne Rech Nucl, ISOLDE, CH-1211 Geneva, Switzerland

[5] Univ Cologne, Inst Kernphys, D-50937 Cologne, Germany

[6] GANIL, F-14076 Caen, France

[7] Katholieke Univ Leuven, Inst Kern & Stralingsfys, B-3001 Louvain, Belgium

[8] Lund Univ, Dept Nucl Phys, S-22100 Lund, Sweden

[9] Univ Michigan, Dept Phys, Ann Arbor, MI 48104 USA

[10] Univ Edinburgh, Sch Phys & Astron, Edinburgh EH9 3JZ, Midlothian, Scotland

[11] Ctr Etud Energie Nucl, SCK CEN Studiectr Kernenergie, B-2400 Mol, Belgium

[12] Univ Jyvaskyla, Dept Phys, FI-40014 Jyvaskyla, Finland

[13] Helsinki Inst Phys, FI-00014 Helsinki, Finland

[14] Univ York, Dept Phys, York YO10 5DD, N Yorkshire, England

[15] Univ Warsaw, Heavy Ion Lab, PL-02093 Warsaw, Poland

[16] Lawrence Livermore Natl Lab, Div Phys, Livermore, CA 94551 USA

[17] Univ Munich, Maier Leibnitz Lab, D-85748 Garching, Germany

[18] Tech Univ Munich, D-85748 Garching, Germany

[19] Univ Autonoma Madrid, Dept Fis Teor, E-28049 Madrid, Spain

[20] Tech Univ Munich, Phys Dept E12, D-85748 Garching, Germany

[21] CEA Saclay, DSM IRFU SPhN, F-91191 Gif Sur Yvette, France

来源：

NATURE | 2013年 / 497卷 / 7448期

基金：

芬兰科学院; 美国国家科学基金会;

关键词：

E4 TRANSITION MOMENTS; COULOMB-EXCITATION; REFLECTION ASYMMETRY; DIPOLE-MOMENTS; DATA SHEETS; STATES; QUADRUPOLE; ISOTOPES; DETECTOR; MODEL;

D O I：

10.1038/nature12073

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

There is strong circumstantial evidence that certain heavy, unstable atomic nuclei are 'octupole deformed', that is, distorted into a pear shape. This contrasts with the more prevalent rugby-ball shape of nuclei with reflection-symmetric, quadrupole deformations. The elusive octupole deformed nuclei are of importance for nuclear structure theory, and also in searches for physics beyond the standard model; any measurable electric-dipole moment (a signature of the latter) is expected to be amplified in such nuclei. Here we determine electric octupole transition strengths (a direct measure of octupole correlations) for short-lived isotopes of radon and radium. Coulomb excitation experiments were performed using accelerated beams of heavy, radioactive ions. Our data on Rn-220 and Ra-224 show clear evidence for stronger octupole deformation in the latter. The results enable discrimination between differing theoretical approaches to octupole correlations, and help to constrain suitable candidates for experimental studies of atomic electric-dipole moments that might reveal extensions to the standard model.

引用

页码：199 / 204

页数：6

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