1. Alpha decay half-lives of even-even superheavy elements
报告人：王永佳
指导老师：张鸿飞
兰州大学核科学与技术学院
第13届核结构讨论会 内蒙古赤峰学院

2. Outline Summary Introduction Generalized Liquid Drop Model (GLDM)
Numerical  results and discussions
Summary

3. Introduction In 1911, Geiger -Nuttall law: Difference:
In 1928, G. Gamow created the QM theory of alpha decay.
1928
In 1928, W. Gurney and U. Condon obtained a general idea of
the mysterious instability of the nucleus.
Difference:
Gurney and Condon argued that the same QM tunneling analysis should also be applicable to beta decay, whereas Gamow already knew that beta decay posed a much deeper theoretical challenge.

4. Various models Theoretical models: Semi-empirical formula:
Viola–Seaborg–Sobiczewski:
G. Royer and H.F. Zhang :
Theoretical models:
Cluster model, DDCM , GDDCM
GLDM, DDM3Y, unified fission model
[Ref.] J. Phys. G: Nucl. Part. Phys. 35 (2008)

5. Introduction Superheavy elements Decay modes: alpha decay
and spontaneous fission
Identification 
Dubna: 48Ca+249Bk ,294117
GSI : 48Ca+244Pu ,289114
[Ref.] Phys. Rev. Lett. 104(2010)
[Ref.] Phys. Rev. Lett. 104(2010)

6. Our method Generalized liquid drop model (GLDM) Preformation factor
Assault frequency
[For heavy even-even nuclei Z>82 and N>126]
The standard deviation between the extracted data and the values obtained from this Eq. is only , implying that the average deviation between the theoretical estimates and the experimental data for alpha decay half-lives of heavy even-even nuclei will be = 1.45.
[Ref.] wang yong-jia and zhang hong-fei at el. CHIN. Phys. Lett. 27(6)

7. Alpha decay energy
[Ref.] T. Dong and Z. Ren, Phys. Rev. C 77, (2008).
[Ref.] B. Buck, A. C. Merchant and S. M. Perez, Phys. Rev. C45(1992), 2247.
[Ref.] E.L. Medeiros et al. , J. Phys. G 32(2006) B23.

8. Alpha decay energy The previously mentioned formula can be simplified:
Royer formula:
[Ref.] G. Royer and H. F. Zhang Phys. Rev. C
[Ref.] Jianmin Dong at el. Phys. Rev. C81(2010)064309

9. Compared with experimental dataAZ
Qexp(MeV)
QDong(MeV)
T(exp.)
T(cal.)
294118
11.81±0.06
11.718
0.89(+1.07/-0.31)ms
0.94ms
292116
10.80±0.07
10.810
18(+16/-6)ms
48.4ms
290116
11.00±0.0.08
11.087
7.1(+3.2/-1.7)ms
16.1ms
288114
10.09±0.07
10.164
0.69 (+0.17/-0.11)s
0.827s
286114
10.33±0.06
10.447
0.26s
0.18s
284112 SF
9.510
99(+24/-16)ms
29.34s
282112
9.799
0.82(+0.30/-0.18)ms
1.56s
270110
11.24±0.05
11.092
100(+140/-40)s
0.93s
266108
10.38±0.02
10.481
2.3(+1.3/-0.6)ms
2.32ms

10. Compared with experimental dataAZ
Qexp(MeV)
QDong(MeV)
T(exp.)
T(cal.)
264108
10.848
10.766
81s
20.5s
260106
9.92±0.03
10.155
9.5(+2/-2)ms
8.1ms
260104
8.947
8.935 1s
0.846s
258104
9.296
9.238
92ms
82.5ms
256104
8.966
9.109
0.304s
0.596s
Experimental Data come from:
Yu. Ts. Oganessian et al., Phys. Rev. C 69, (R) (2004);70, (2004);
72, (2005); 74, (2006); 76, (R) (2007)
and G. Audi et al. Nucl. Phys. A 729 (2003) 3.

11. Superheavy elements Cold fusion：Z<113 Hot fusion：48Ca， 56Fe ：
Dubna: Ca+Pu，Am，Cm，Bk，Cf
GSI: Ca+Pu Ds---277Hs+alpha
Future: Ca + Md
Fe + Md
Nuclei which Z<127 would be synthesized
in the near future.

12. Alpha decay and spontaneous fission
Phys. Rev. C78(2008)
For 45 nuclei
Region from 232Th to

13. Very long SF half-life, why?
Z. Ren, et al. NPA 759 (2005) 64.
Chang Xu, et al. PRC78 (2008)
K.P. Santhosh et al. NPA832(2010)220

14. Summary We improved the assault frequency in the GLDM.
The improved model agrees with the experimental data of heavy nuclei within a factor of 2.
General predictions

15. Thanks for your attention!
Thanks for the organizer of this conference!