Projected shell model description for nuclear isomers

Yang Sun

Department of Physics, Shanghai Jiao Tong University, Shanghai 200240, P.R. China, Joint Institute for Nuclear Astrophysics, University of Notre Dame, Notre Dame, Indiana 46545, USA.

Recibido el 10 de marzo de 2008
Aceptado el 7 de mayo de 2008

Abstract

The study of nuclear isomer properties is a current research focus. To describe isomers, we present a method based on the Projected Shell Model. Two kinds of isomers, K–isomers and shape isomers, are discussed. For the K–isomer treatment, K–mixing is properly implemented in the model. It is found however that in order to describe the strong K–violation more efficiently, it may be necessary to further introduce triaxiality into the shell model basis. To treat shape isomers, a scheme is outlined which allows mixing those configurations belonging to different shapes.

Keywords: Shell model; nuclear energy levels.

Resumen

Se estudian las propiedades de isómeros nucleares a través del modelo de capas proyectadas. Se discutan isómeros K y de forma nuclear. Para discutir las propiedades de los isómeros K se tiene que incluir la mezcla de diferentes valores K en el modelo así como la deformación triaxial. A los isómeros de forma se pueden tratar en un modelo que permita la mezcla de configuraciones con formas nucleares distintas.

Descriptores: Modelo de capas; niveles de energía nucleares.

PACS:21.60.Cs;21.10.–k

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Acknowledgements

The author is grateful to J. Hirsch and V. Velazquez for warm hospitality during the Cocoyoc 2008 meeting. He acknowledges helpful discussions with A. Aprahamian, Y. R. Shimizu, P. M. Walker, and M. Wiescher. This work is supported by the Chinese Major State Basic Research Development Program through grant 2007CB815005 and by the U. S. National Science Foundation through grant PHY–0216783.

References

1. P.M. Walker and R.C. Johnson, Nature Phys. 3 (2007) 836.        [ Links ]

2. I. Mukha et al., Phys. Rev. Lett. 95 (2005) 022501.        [ Links ]

3. I. Mukha et al., Nature 439 (2006) 298.        [ Links ]

4. P.M. Walker and G.D. Dracoulis, Nature 399 (1999) 35.        [ Links ]

5. M. Hasegawa, Y. Sun, K. Kaneko, and T. Mizusaki, Phys. Lett. B 617 (2005) 150.        [ Links ]

6. E. Bouchez, et al., Phys. Rev. Lett. 90 (2003) 082502.        [ Links ]

7. A. Blazhev, et al., Phys. Rev. C 69 (2004) 064304.        [ Links ]

8. Y. Sun, X.–R. Zhou, G.–L. Long, E.–G. Zhao, and P. M. Walker, Phys. Lett. B 589 (2004) 83.        [ Links ]

9. P.M. Walker and J.J. Carroll, Physics Today (June issue) (2005) 39.        [ Links ]

10. F.–R. Xu, E.–G. Zhao, R. Wyss, and P.M. Walker, Phys. Rev. Lett. 92 (2004) 252501.        [ Links ]

11. R.–D. Herzberg et al., Nature 442 (2006) 896.        [ Links ]

12. A. Aprahamian and Y. Sun, Nature Phys. 1 (2005) 81.        [ Links ]

13. R.C. Runkle, A.E. Champagne, J. Engel, Astrophys. J. 556, (2001) 970.        [ Links ]

14. Y. Sun, M. Wiescher, A. Aprahamian, and J. Fisker, Nucl. Phys. A 758 (2005) 765.        [ Links ]

15. K. Hara and Y. Sun, Int. J. Mod. Phys. E 4 (1995) 637.        [ Links ]

16. Y. Sun and K. Hara, Comp. Phys. Commun. 104 (1997) 245.        [ Links ]

17. K. Jain et al., Nucl. Phys. A 591 (1995) 61.        [ Links ]

18. V.G. Soloviev, Nucl. Phys. A 633 (1998) 247.        [ Links ]

19. J.–Y. Zeng, S.–X. Liu, L.–X. Gong, and H.–B. Zhu, Phys. Rev. C 65 (2002) 044307.        [ Links ]

20. M. Dufour and A.P. Zuker, Phys. Rev. C 54 (1996) 1641.        [ Links ]

21. S.M. Mullins et al., Phys. Lett. B 393 (1997) 279; Phys. Lett. B 400 (1997) 401.        [ Links ]

22. Y. Sun and J.L. Egido, Nucl. Phys. A 580 (1994) 1.        [ Links ]

23. G.D. Dracoulis et al., Phys. Rev. C 71 (2005) 044326.        [ Links ]

24. G.D. Dracoulis et al., Phys. Lett. B 635 (2006) 200.        [ Links ]

25. C.S. Purry et al., Nucl Phys. A 632 (1998) 229.        [ Links ]

26. K. Narimatsu, Y.R. Shimizu, and T. Shizuma, Nucl Phys. A 601 (1996) 69.        [ Links ]

27. Y. Sun et al., Phys. Rev. C 61 (2000) 064323.        [ Links ]

28. Z.–C. Gao, Y.–S. Chen, and Y. Sun, Phys. Lett. B 634 (2006) 195.        [ Links ]

29. J.A. Sheihk, G.H. Bhat, Y. Sun, G.B. Vakil, and R. Palit, Phys. Rev. C, 77 (2008) 034313.        [ Links ]

30. Y. Sun, Eur. Phys. J. A 20 (2004) 133.        [ Links ]

31. K. Kaneko, M. Hasegawa, and T. Mizusaki, Phys. Rev. C 70, (2004) 051301(R).        [ Links ]

32. H. Schatz et. al., Phys. Rep. 294 (1998) 167.        [ Links ]

33. D.J. Thouless, Nucl. Phys. 21 (1960) 225.        [ Links ]

34. K. Tanabe, K. Enami and N. Yoshinaga, Phys. Rev. C 59 (1999) 2492.        [ Links ]

35. Z.–C. Gao, Y. Sun, and Y.–S. Chen, Phys. Rev. C 74 (2006) 054303.        [ Links ]