稀土区原子核的形状变化和形状共存 华 辉 北京大学物理学院 2010年7月25-27日全国核结构会议 赤峰

Shapes of atomic nuclei 一. 引言 Shapes of atomic nuclei Prolate Oblate Quadrupole deformation of the nuclear ground states M. Girod, CEA Bruyères-le-Châtel Few nuclei have oblate ground states (~86% are prolate in their ground state) Phys Rev C64 (2001) 037301

Shape evolution along with neutron number protons neutrons 82 50 28 20 8 2 126 Deformed Spherical

Evolution of nuclear shape New analytical solutions, E(5) and X(5) R4/2= ~2.0 R4/2= 3.33

X(5) Key Signatures E(41)/E(21) = 2.91 E(02)/E(21) = 5.67 E(5) X(5) E(5) Key Signatures Deformed E(5) Sph. X(5) Key Signatures E(41)/E(21) = 2.91 E(02)/E(21) = 5.67 X(5) 1)F. Iachello, PRL85, 3580(2000); PRL87, 052502(2001) 2)D.D. Warner, Nature 420 (2002) 614

Transitional Rotor Vibrator

Energy 148Sm 152Sm 154Sm Deformation Vibrator Soft Rotor Spherical Transitional Deformed Energy Deformation

Shape evolution along with angular momentum 65hbar! 1)Paul et al., PRL 98, 012501 (2007). 2)M.A. Riley et. al, ACTA PHYSICA POLONICA B40, 513(2009)

Regan, et al., PRL 90, 152502 (2003)

Triple Shape Coexistence at low excitation energy 186Pb 1)A. Andreyev et al., Nature 405 (2000) 430 2)T. Grahn,- PRL97 (2006) 062501

Triple Shape Coexistence at middle excitation energy 135Ba 1)Kumar et al., PRC81 (2010) 067104; 2)X.L. Che, S.J. Zhu et al., Eur. Phys. J. A 30, 347(2006)

Shape Coexistence in the N=87 isotones

二.稀土区原子核的形状研究@PKU 稀土区原子核的形状

实验方法 Inelastic scattering Transfer reactions Fusion

实验 148Nd (9Be, 5n) 152Gd@2004 束流: 54MeV 9Be beam 靶: 148Nd target (1.1mg/cm2)   　　　　　　　　　　　　 144Sm(16O, 4n)156Yb@2006 束流: 102MeV 16O beam 靶: 144Sm target (1.2mg/cm2)   144Sm(16O, 3n)157Yb@2009 束流: 85MeV 16O beam 靶: 144Sm target (3.1mg/cm2)   测量装置:   退激 -射线 ------ Gamma array of CIAE

C. Xu, H. Hua et al., Submitted

ni13/2 nf7/2 nh9/2

波函数成分的分析 I= 7/2- 26.9 keV I= 11/2- 350 keV I= 15/2- 1011 keV 20: 0.626 20: 0.641 20: 0.650 f7/2 1/2[541] 21: 0.289 21: 0.283 21: 0.278 22:-0.588 22:-0.565 22:-0.553 f7/2 3/2[532] 23: 0.316 23: 0.298 23: 0.287 24: 0.238 24: 0.264 24: 0.276 25:-0.138 25:-0.151 25:-0.155 26:-0.064 26:-0.079 27:-0.064 27:-0.079 I= 9/2- 0 keV I= 13/2- 325 keV I= 17/2- 987 keV 20: 0.291 20: 0.286 20: 0.284 21:-0.683 21:-0.673 21:-0.666 h9/2 1/2[530] 22: 0.447 22: 0.422 22: 0.409 23: 0.387 23: 0.410 23: 0.420 h9/2 3/2[521] 24: 0.285 24: 0.294 24: 0.298 h9/2 5/2[523] 25: 0.099 25: 0.131 25: 0.149 26: 0.081 26: 0.106 26: 0.119 27:-0.064 27:-0.080

Band 3 Band 4

三. 研究展望

主 要 合 作 者 竺礼华，吴晓光，李广生，温书贤， 贺创业，崔兴柱，刘颖等 （中国原子能科学研究院核物理所） 王守宇 （山东大学威海分校） 周善贵 （中国科学院理论物理所）

谢 谢 !!