1. 南京大学 物理系 超重核 ( 新元素 ) 研究进展 任中洲 南京大学 物理系 寻找重元素的历史回顾 实验的新进展 理论研究状况 Z=118 新元素的合成 (Dubna)

2. 周期表 (1869): 门捷列夫未获 Nobel Prize

3. 周期表 (2000s)

4. 1 寻找重元素的历史 早期物理学家寻找新化学元素 物理学 + 化学 : 光谱线 : Fraunhofer, Kirchhoff +Bunsen (Germany): Cs, Rb (37,55); Crookes, Tl(81). 物理学 + 天文学 : 日蚀时，观察新光谱线 ，太阳元素：氦 法国物理学家，英国天文学家（ 1868 ）. 为什么物理学家介入：物理方法威力大。

5. 1903-1904: Nobel Prize and new elements 1. Rayleigh (physicist: N) +Ramsy (chemist): Ar; He (Crookes: confirm), Ne,Kr 1904 Nobel prize ( Physics+Chemistry) 2. M. Curie and P. Curie: Radioactivity; Stronger : new elements, Ra, Po (1898) ? 1903 Nobel prize (Physics) 1/2+(1/4+1/4) 1911 Nobel prize (Chemistry)

6. References on arguments 1. A history of physics, Dover Publications, F. Cajori, 1962, USA. 2. Une Femme Honorable, Marie Curie; De Francoise Giroud; Librairie Artheme Fatard, 1981. 3. A short history of nearly everything, Bill Bryson, Jed Mattes Inc., 2003

7. Lord Kelvin

10. 1 寻找新元素的历史 周期表中 30 多个元素由核方法合成 1930—1949 找到 “ 失踪 ” 元素 重元素 （ U 以后： Z=93,94?) 合成 核合成的元素被化学家证实 为什么核合成？ 稀有 或 放射性。

11. Year of discovery (1896-1996)

12. 重元素合成的意义 （ 1 ） 扩展元素周期表 到底有多少个化学元素 ？ 新元素的应用？超重岛存在？ 超重岛存在机制？ 新现象？

13. 元素的命名 Z=101, Md, Mendelevium. (Berkeley). Z=102, No. Nobelium (Berkeley +Nobel) Z=103, Lr, Lawrencium. (Berkeley) Z=104, Rutherfordium. (Berkeley;Dubna) ? Z=105, Db, Dubnium (Dubna;Berkeley) ? Z=106, Seaborgium. (Dubna;Berkeley) ? Z=107, Bohrium (Dubna) Z=108, Hassium (GSI; Dubna) ??? Z=109, Meitnerium. (GSI) Z=110, Darmstadium…. (GSI)

14. New elements Z=114 and Z=116 (Dubna)

15. Z=114, nature

16. 2. Summary of New Results The elements Z=110,111,112 were produced at GSI, Hofmann, Muenzenberg…. Z. Phys. A, 1995, 1996. Z=114 was synthesized at Dubna by Oganessian et al. Nature, 1999; Phys. Rev. Lett. 1999;Phys. Rev. C, 2000. Z=116, Z=115, Z=118 were produced at Dubna in 2000s. Oganessian et al, Phys. Rev. C, 2001-2006. Z=113, RIKEN; PSI: 270 108; GSI: 270 110 ; Lanzhou: 265 107…. 继续争论？？？ 新元素？？？

17. 超重新核素 259 Db (Z=105), 265 Bh (Z=107) 中科院近代物理研究所 259 Db 0. 5 s 9.47  265 Bh 0.94 s 9.24 

18. 国内超重新核素实验 265Bh (Z=107) 265Bh 的实验结果与理论预言一致

19. 3. theory. J. A. Wheeler et al, 1950s: Superheavy nuclei P.R., 1958. Bethe and his collaborator, PRL, 1967. 1960s-1980s, macroscopic-microscopic model (MM): Nilsson et al, Z=114 and N=184 ? Moeller, Nix, Kratz, At. Dat. Nu. Dat. 1997. Myers and Swiatecki, PRC, 1998.

20. Werner and Wheeler, PR, 1958: superheavy nuclei

21. Siemens and Bethe: nuclei with Z>104 are prolate

22. 3. Theory ( SHF and RMF 1990--) Zhongzhou REN et al, JPG, 1996; CPL, 1997. Lalazissis, Ring et al, NPA, 1996. Cwiok, Nazarewicz, Heenen, PRL, 1999. Ren and Toki, Nucl. Phys. A689 (2001) 691: Z=110-112,114. Ren, PRC, 2002,May,(R);PRC, Dec.,2002 Ren et al, PRC 2003, PRC2004, PRC2005...

23. 3. Numerical results and discussion Z: 94—116; N:150—184. Test the model for even-even nuclei: Comparison of RMF model and Moeller result for the alpha chain of 277 112. * Theoretical decay energy for Z=110-112. Theoretical decay energy for Z=114, 116. Nuclear structure : Shape coexistence in superheavy nuclei

24. Fig. 3 Theoretical and experimental alpha decay energies for GSI Data: Z=110, 111, 112 ( +2, +1, 0 shift).

25. NucleiB the. (1)Beta p B the. (2)Beta p B exp. (MeV) 244 Cf1832.90.261829.70.311831.3 246 Cf1846.30.271843.10.311844.8 248 Cf1859.00.261855.50.311857.8 250 Cf1871.00.261866.90.311870.0 252 Cf1882.40.261877.80.311881.3 254 Cf1892.90.251888.50.301892.1 Table 1, RMF results for Cf. (TMA and NLZ2) Experimental deformation Beta 2 =0.30 for 250,252 Cf

26. NucleiB the. (1)Beta p B the. (2)Beta p B exp. (MeV) 252 No1873.20.261870.70.311871.3 254 No1887.20.271884.10.311885.6 256 No1900.70.271897.00.311898.6 258 No1912.90.271909.60.301911.1 audi 260 No1924.60.261921.70.301923.1 audi 262 No1935.80.211933.10.291934.7 audi Table 2, RMF results for No. (TMA and NLZ2) Experimental deformation Beta 2 =0.27 for 254 No

27. Fig. 1 Energy surface of Z=108, A=264

28. Experimental B/A (MeV) is between two sets of RMF results (Z=98-108).

29. Fig. 2 Binding energy of the Z=112, A=277 chain from the RMF and Moller et al.

30. NucleiB the. Beta n Beta p Q the. Q exp. 269 1101954.40.220.2311.5611.13 265 1081937.70.240.259.9210.57 261 1061919.30.250.269.179.58 257 1041900.10.26 8.618.71 253 1021880.50.260.278.258.14 Tab. 4, results for GSI data 269 110. (TMA)

31. Fig. 4 Theoretical and experimental alpha decay energy for Z=114, A=289 and Z=118, A=293

32. 创新点及意义 (1) 提出超重核形状共存 ---- 可能是超重核存在新机制 : 改进和发展了数值计算方法和程序 完成大规模数值计算 提出超重核形状共存, 形变重要, 有低能同质异能态 发表了一系列论文 (PRC 3 篇 ; NPA 2 篇等 ) 论文被国外同行引用和肯定 : 论文被国际上著名实验小组引用 (Dubna-Livemore- PSI) 论文被综述文章引用 (Nature, PRC, JPG)

33. 南京大学 Predictions of SHF and RMF compare well with MM results [12,13] Oganessian et al, PRC72 2005

34. 南京大学 SHF [12 ， 49-51] and RMF [13 ， 52-57] compare well with the experimental results Oganessian et al, PRC72 2005

35. Sharma,… Stevenson, Gupta, Greiner agree with us: shape coexistence and superdeformation

36. Geng, Toki, Zhao: similar results with us.

37. Geng, Toki, Zhao JPG 32 (2006) 573: shape coexistence and superdeformation.

38. Other RMF calculations agree with ours: superdeformation in superheavy nuclei

39. 配合国内实验, 理论预言 : 265 107 Q a and T a Z. Ren et al, PRC 67 (2003) 064302; JNRS 3 (2002) 195. AXAX B (MeV) Beta n Beta p Q a (MeV) T a (second) 269 1091960.170.220.2310.210.069 265 1071942.080.230.249.412.56 261 1051923.190.26 9.143.33 257 1031904.030.260.278.121.28*10 3 Expt: Gan et al, EPJA 2004, Q a =9.38, T a =0.94 s. Good agreement between theory and data.

40. 国内超重新核素实验 265Bh (Z=107) 265Bh 的实验结果与理论预言一致

41. 3. Density-Dependent Cluster Model DDCM is a new model of alpha and cluster decay: 1) effectve potential based on the Reid potential. 2) low density behavior included. 3) exchange included 4) agreement within a factor of three for half-lives Z Ren, C Xu, Z Wang, PRC 70: 034304 (2004) C Xu, Z Ren, NPA 753: 174 (2005) C Xu, Z Ren, NPA 760: 303 (2005) C. Xu, Z. Ren, PRC 73: 041301(R) (2006)…

42. DDCM for superheavy nuclei (Z=106-118)

43. Density-Dependent Cluster Model 建立了球形和形变核双折叠势程序 推导了球形，形变核 alpha 衰变寿命公式 对已知 alpha 衰变寿命进行了大规模计算 对结团放射性进行了系统研究

45. Deformed DDCM: a spherical alpha-particle interacts with a deformed daughter nucleus with an axially symmetric deformation

46. The distribution of the number of alpha emitters for different factors of agreement (Even-Even).

47. The comparison of experimental alpha-decay half-lives and theoretical ones for even-even nuclei (Z= 52−104)

49. Synthesis of new element Z=118 1. 2002, Dubna: D7-2002-287 2. PRC69, 2004 (May). 3. PRC70, 2004 (Dec.). 4. Phys. Scrt. 2006 (June) 5. PRC 74, 2006 (October).

50. Oganessian PRC69 (2004): Z=118

53. Oganessian PRC74 (2006): Z=118

54. APS: Physics News Update October

55. Xu and Ren, PRC 69 (2004) (Feb.)

56. 3. Summary (1) The properties of even-even nuclei with Z=94— 116 are investigated in the RMF model. The constraint RMF calculation shows clearly the coexistence of shape in superheavy nuclei. This is useful for a deeper binding and may be a new mechanism of appearance of superheavy islands.

57. 3. Summary (2) We propose a new model of alpha decay: Density-dependent cluster model (DDCM) Two versions: spherical and deformed. Agree well with known data. Good prediction for unknown half-lives.

58. Various shapes of superheavy nuclei Old picture: Spherical. Z=114 and N=184. Prof. Greiner: Fullerene (Buckyball, 60 C). (sixty alpha particles for Z=120 ) Our idea: American football. (Isomers) ( shape coexistence or superdeformation). Which shape do you prefer ?

59. Superheavy nuclei: American football; round ball; Soccer ( 60 C)

60. To produce Z=117 element in China? We estimate the alpha-decay energies and half- lives of Z=117 elements. We will estimate the spontaneous fission half-lives of Z=117 element. The goal of 973 of Nuclear Physics: 2007-2012

61. 谢 谢！ THANKS!