Nuclear Physics and Atomic Energy

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Nuclear Physics and Atomic Energy

  ISSN: 1818-331X (Print), 2074-0565 (Online)
  Publisher: Institute for Nuclear Research of the National Academy of Sciences of Ukraine
  Languages: Ukrainian, English, Russian
  Periodicity: 4 times per year

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Nucl. Phys. At. Energy 2019, volume 20, issue 2, pages 111-125.
Section: Nuclear Physics.
Received: 28.03.2019; Accepted: 11.07.2019; Published online: 27.08.2019.
PDF Full text (en)
https://doi.org/10.15407/jnpae2019.02.111

Two-neutron transfer reactions and the quantum chaos measure of nuclear spectra

A. I. Levon, A. G. Magner*

Institute for Nuclear Research, National Academy of Sciences of Ukraine, Kyiv, Ukraine

*Corresponding author. E-mail address: magner@kinr.kiev.ua

Abstract: A new statistical interpretation of the nuclear collective states is suggested and applied to analysis of states, found recently in rare earths and actinide nuclei by the two-neutron transfer reactions, in terms of the nearest neighbor-spacing distributions (NNSDs). Experimental NNSDs were obtained by using the complete and pure sequences of the collective states through an unfolding procedure. The two-neutron transfer reactions allow to obtain such a sequence of the collective states that meets the requirements for a statistical analysis. Their theoretical analysis is based on a linear approximation of the repulsion level density within the Wigner - Dyson theory. This approximation is successful to evaluate separately the Wigner chaos and Poisson order contributions. We found an intermediate behavior of NNSDs between the Wigner and Poisson limits. NNSDs turn out to be shifted from a chaos to order with increasing the length of spectra and the angular momentum of collective states. The symmetry breaking of states with the fixed projection of angular momenta K is discussed in terms of degree of symmetry – the number of independent integrals of motion beyond the system energy – in relation to the periodic orbit theory.

Keywords: statistical analysis, nuclear collective states, quantum and classical chaos, nearest neighbor-spacing distributions, Wigner and Poisson distributions.

References:

1. M.L. Mehta. Random Matrices (San Diego, New York, Boston, London, Sydney, Tokyo, Toronto: Academic Press, 1991). Google books

2. V. Zelevinsky et al. The nuclear shell model as a testing ground for many for many-body quantum chaos. Phys. Rep. 276 (1996) 85. https://doi.org/10.1016/S0370-1573(96)00007-5

3. H.-J. Stöckmann. Quantum Chaos: An Introduction (Cambridge, University Press, Cambridge, England, 1999). https://doi.org/10.1017/CBO9780511524622

4. S. Aberg. Quantum Chaos (Lund: Mathematical Physics, 2002).

5. H.A. Weidenmuller, G.E. Mitchell. Random matrix and chaos in nuclear physics: nuclear structure. Rev. Mod. Phys. 81 (2009) 539. https://doi.org/10.1103/RevModPhys.81.539

6. G.E. Mitchell, A. Richter, H.A. Weidenmuller. Random matrix and chaos in nuclear physics: nuclear reactions. Rev. Mod. Phys. 82 (2010) 2845. https://doi.org/10.1103/RevModPhys.82.2845

7. J.M.G. Gomez et al. Many-body quantum chaos. Recent developments and applications to nuclei. Phys. Rept. 499 (2011) 103. https://doi.org/10.1016/j.physrep.2010.11.003

8. F. Iachello, A. Arima. The Interacting Boson Model (Cambridge, England: Cambridge University Press, 1987). https://doi.org/10.1017/CBO9780511895517

9. V.G. Soloviev. Theory of Atomic Nuclei: Quasiparticles and Phonons (Bristol: Institute of Physics, 1992). Google books

10. B. Gremaud, S.R. Jain. Spacing distributions for rhombus billiards. J. Phys. A 31 (1998) L637. https://doi.org/10.1088/0305-4470/31/37/003

11. E.B. Bogomolny, U. Gerland, C. Schmit. Models of intermediate spectral statistics. Phys. Rev. E 59 (1999) R1315(R). https://doi.org/10.1103/PhysRevE.59.R1315

12. V.V. Flambaum et al. Structure of compound states in the chaotic spectrum of the Ce atom. Phys. Rev. A 50 (1994) 267. https://doi.org/10.1103/PhysRevA.50.267

13. V.V. Flambaum, G.F. Gribakin, F.M. Izrailev. Correlations within Eigenvectors and Transition Amplitudes in the Two-Body Random Interaction Model. Phys. Rev. E 53 (1996) 5729. https://doi.org/10.1103/PhysRevE.53.5729

14. S.H. Tekur, S. Kumar, M.S. Santhanam. Exact distribution of spacing ratios for random and localized states in quantum chaotic systems. Phys. Rev. E 97 (2018) 062212. https://doi.org/10.1103/PhysRevE.97.062212

15. S.H. Tekur, U.T. Bhosale, M.S. Santhanam. Exact distribution of spacing ratios for random and localized states in quantum chaotic systems. Phys. Rev. E 97 (2018) 062212. https://doi.org/10.1103/PhysRevE.97.062212

16. O. Bohigas, M.J. Giannoni, C. Schmit. Characterization of chaotic quantum spectra and universality of level fluctuations. Phys. Rev. Lett. 52 (1984) 1. https://doi.org/10.1103/PhysRevLett.52.1

17. E.P. Wigner. On the statistical distribution of the width and spacings of nuclear resonance level. Proc. Philos. Soc. 47 (1951) 790. https://doi.org/10.1017/S0305004100027237

18. T.A. Brody. A statistical measure for the repulsion of energy levels. Lett. Nuovo Cimento 7 (1973) 482. https://doi.org/10.1007/BF02727859

19. M.V. Berry, M. Robnik. Semiclassical level spacings when regular and chaotic orbits coexist. J. Phys. A 17 (1984) 2413. https://doi.org/10.1088/0305-4470/17/12/013

20. F.M. Izrailev. Quantum localization and statistics of quasi-energy spectrum in a classically chaotic system. Phys. Lett. 134 (1988) 13. https://doi.org/10.1016/0375-9601(88)90538-5

21. C.E. Porter. Statistical Theories of Spectra: Fluctuations (New York: Academy Press, 1965). Google books

22. M.V. Berry. Quantizing a classically ergodic system: Sinai’s billiard and the KKR method. Ann. Phys. 131 (1981) 163. https://doi.org/10.1016/0003-4916(81)90189-5

23. T.A. Brody et al. Random-matrix physics: spectrum and strength fluctuations. Rev. Mod. Phys. 53 (1981) 385. https://doi.org/10.1103/RevModPhys.53.385

24. S.R. Jain, A. Khare. Exactly Solvable Many-Body Problem in One Dimension. Phys. Lett. A 262 (1999) 35. https://doi.org/10.1016/S0375-9601(99)00637-4

25. Z. Ahmed, S.R. Jain. Pseudo-unitary symmetry and the Gaussian pseudo-unitary ensemble of random matrices. Phys. Rev. E 67 (2003) 0451006 (R). https://doi.org/10.1103/PhysRevE.67.045106

26. J.F. Shriner Jr., G.E. Mitchell, T. von Egidy. Fluctuation Properties of Spacings of Low-Lying Nuclear Levels. Z. Phys. A 338 (1991) 309. https://doi.org/10.1007/BF01288195

27. J.F. Shriner Jr. et al. Fluctuation Properties of States in 26Al. Z. Phys. A 335 (1990) 393. https://doi.org/10.1007/BF01290186

28. J.F. Shriner Jr., C.A. Grossmann, G.E. Mitchell. Level statistics and transition distributions of 30P. Phys. Rev. C 62 (2004) 054305. https://doi.org/10.1103/PhysRevC.62.054305

29. G. Vidmar et al. Beyond the Berry-Robnik regime: a random matrix study of tunneling effects. J. Phys. A 40 (2007) 13803. https://doi.org/10.1088/1751-8113/40/46/005

30. B. Dietz et al. Chaos and regularity in the doubly magic nucleus 208Pb. Phys. Rev. Lett. 118 (2017) 012501; https://doi.org/10.1103/PhysRevLett.118.012501

L. Munoz et al. Examination of experimental evidence of chaos in the bound states of 208Pb. Phys. Rev. C 95 (2017) 014317. https://doi.org/10.1103/PhysRevC.95.014317

31. J.P. Blocki, A.G. Magner. Chaoticity and shell corrections in the nearest-neighbor distributions for an axially-symmetric potential. Phys. Rev. C 85 (2012) 064311. https://doi.org/10.1103/PhysRevC.85.064311

32. A.I. Levon, A.G. Magner, S.V. Radionov. Statistical analysis of excitation energies in actinide and rare-earth nuclei. Phys. Rev. C 97 (2018) 044305. https://doi.org/10.1103/PhysRevC.97.044305

33. A.G. Magner, A.I. Levon, S.V. Radionov. Simple approach to the chaos-order contributions in nuclear spectra. Eur. Phys. J. A 54 (2018) 214. https://doi.org/10.1140/epja/i2018-12645-8

34. A.I. Levon et al. The nuclear structure of 229Pa from the 231Pa(p,t)229Pa and 230Th(p,2n)229Pa reactions. Nucl. Phys. A 576 (1994) 267. https://doi.org/10.1016/0375-9474(94)90260-7

35. A.I. Levon et al. Spectroscopy of 230Th in the (p,t) reaction. Phys. Rev. C 79 (2009) 014318. https://doi.org/10.1103/PhysRevC.79.014318

36. A.I. Levon et al. 0+ states and collective bands in 228Th studied by the (p,t) reaction. Phys. Rev. C 88 (2013) 014310. https://doi.org/10.1103/PhysRevC.88.014310

37. A.I. Levon et al. Spectroscopy of 232U in the (p,t) reaction: More information on 0+ excitations. Phys. Rev. C 92 (2015) 064319. https://doi.org/10.1103/PhysRevC.92.064319

38. M. Spieker et al. Possible experimental signature of octupole correlations in the 0+2 states of the actinide. Phys. Rev. C 88 (2013) 041303(R). https://doi.org/10.1103/PhysRevC.88.041303

39. M. Spieker et al. Higher-resolution (p,t) study of low-spin states in 240Pu: Octupole excitations, α clustering and other structure features. Phys. Rev. C 97 (2018) 064319. https://doi.org/10.1103/PhysRevC.97.064319

40. M. Gutzwiller. Periodic orbits and classical quantization conditions. J. Math. Phys. 12 (1971) 343. https://doi.org/10.1063/1.1665596

41. M. Gutzwiller. Chaos in Classical and Quantum Mechanics (N.Y.: Springer-Verlag, 1990). https://doi.org/10.1007/978-1-4612-0983-6

42. V.M. Strutinsky. Semiclassical theory for nuclear shell structure. Nucleonica 20 (1975) 679.

43. V.M. Strutinsky, A.G. Magner. Quasiclassical theory of nuclear shell structure. Sov. J. Part. Nucl. 7 (1976) 138.

44. M.V. Berry and M. Tabor. Closed orbits and the regular bound spectrum. Proc. R. Soc. Lond. A 349 (1976) 101. https://doi.org/10.1098/rspa.1976.0062

45. M.V. Berry and M. Tabor. Level clustering in the regular spectrum. Proc. R. Soc. Lond. A 356 (1977) 375. https://doi.org/10.1098/rspa.1977.0140

46. A.G. Magner. Quasiclassical analysis of the gross-shell structure in a deformed oscillator potential. Sov. J. Nucl. Phys. 28 (1978) 759.

47. S.C. Creagh, J.M. Robbins, R.G. Littlejohn. Geometric properties of Maslov indices in the semiclassical trace formula for the density of states. Phys. Rev. A 42 (1990) 1907. https://doi.org/10.1103/PhysRevA.42.1907

48. S.C. Creagh, R.G. Littlejohn. Semiclassical trace formulas in the presence of continuous Symmetries. Phys. Rev. A 44 (1991) 836. https://doi.org/10.1103/PhysRevA.44.836

49. S.C. Creagh, R.G. Littlejohn. Semiclsassical trace formulae for systems with non-Abelian symmetries. J. Phys. A 25 (1992) 1643. https://doi.org/10.1088/0305-4470/25/6/021

50. V.M. Strutinsky et al. Semiclassical interpretation of the gross-shell structure in deformed nuclei. Z. Phys. A 283 (1977) 269. https://doi.org/10.1007/BF01407208

51. M. Brack, R.K. Bhaduri. Semiclassical Physics (USA: Westview Press Boulder, 2003) 458 p. Google books

52. A.G. Magner et al. Shell structure and orbit bifurcations in finite fermion systems. Phys. Atom. Nucl. 74 (2011) 1445. https://doi.org/10.1134/S1063778811100061

53. A.G. Magner, M.V. Koliesnik, K. Arita. Shell, orbit bifurcations, and symmetry restorations in Fermi systems. Phys. Atom. Nucl. 79 (2016) 1067. https://doi.org/10.1134/S1063778816060181

54. A.G. Magner, K. Arita. Semiclassical catastrophe theory of simple bifurcations. Phys. Rev. E 96 (2017) 042206. https://doi.org/10.1103/PhysRevE.96.042206

55. A.M. Ozorio de Almeida, J.H. Hannay. Resonant periodic orbits and the semiclassical energy spectrum. J. Phys. A 20 (1987) 5873. https://doi.org/10.1088/0305-4470/20/17/021

56. A.M. Ozorio de Almeida. Hamiltonian Systems: Chaos and Quantization (Cambridge: University Press, 1988). https://doi.org/10.1017/CBO9780511564161

57. J.P. Blocki, A.G. Magner, I.S. Yatsyshyn. The internal excitation of the gas of independent particles in the time-dependent potential. Int. J. Mod. Phys. E 20 (2011) 292. https://doi.org/10.1142/S0218301311017648

58. J.P. Blocki, A.G. Magner, I.S. Yatsyshyn. The internal excitation of the gas of independent particles in the time-dependent potential. Nucl. Phys. At. Energy 11 (2010) 239. http://jnpae.kinr.kiev.ua/11.3/Articles_PDF/jnpae-2010-11-0239-Blocki.pdf

59. R.F. Casten, D. D. Warner. The interacting boson approximation. Rev. Mod. Phys. 60 (1988) 389. https://doi.org/10.1103/RevModPhys.60.389

60. O. Bohigas, M.P. Pato. Missing levels in correlated spectra. Phys. Lett. B 595 (2004) 171. https://doi.org/10.1016/j.physletb.2004.05.065