Atomic Nuclei

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T Papenbrock - One of the best experts on this subject based on the ideXlab platform.

  • effective field theory for deformed Atomic Nuclei
    Physica Scripta, 2016
    Co-Authors: T Papenbrock, H A Weidenmuller
    Abstract:

    In this paper, we present an effective field theory (EFT) for a model-independent description of deformed Atomic Nuclei. In leading order this approach recovers the well-known results from the collective model by Bohr and Mottelson. When higher-order corrections are computed, the EFT accounts for finer details such as the variation of the moment of inertia with the band head and the small magnitudes of interband E2 transitions. Finally, for rotational bands with a finite spin of the band head, the EFT is equivalent to the theory of a charged particle on the sphere subject to a magnetic monopole field.

  • effective field theory of emergent symmetry breaking in deformed Atomic Nuclei
    Journal of Physics G, 2015
    Co-Authors: T Papenbrock, H A Weidenmuller
    Abstract:

    Spontaneous symmetry breaking in non-relativistic quantum systems has previously been addressed in the framework of effective field theory. Low-lying excitations are constructed from Nambu–Goldstone modes using symmetry arguments only. In this study, we extend that approach to finite systems. The approach is very general. To be specific, however, we consider Atomic Nuclei with intrinsically deformed ground states. The emergent symmetry breaking in such systems requires the introduction of additional degrees of freedom on top of the Nambu–Goldstone modes. Symmetry arguments suffice to construct the low-lying states of the system. Lastly, in deformed Nuclei these are vibrational modes each of which serves as band head of a rotational band.

George Dracoulis - One of the best experts on this subject based on the ideXlab platform.

  • exotic isomers in deformed Atomic Nuclei
    Hyperfine Interactions, 2001
    Co-Authors: P M Walker, George Dracoulis
    Abstract:

    Excited states of Atomic Nuclei can have long half lives, due to the angular-momentum couplings of unpaired nucleons. Such isomeric states provide opportunities for exploring novel nuclear physics, astrophysics and physics at the Atomic/nuclear interface. This review focuses on the properties of isomers in deformed Nuclei, and emphasises the importance of axial symmetry in preserving the integrity of the K quantum number. A region of neutron-rich Nuclei around 188Hf (Z=72, N=116) is predicted to have exceptional isomer properties, and experimental advances are now opening up this region to detailed investigation.

  • energy traps in Atomic Nuclei
    Nature, 1999
    Co-Authors: P M Walker, George Dracoulis
    Abstract:

    A small proportion of Atomic Nuclei can form highly excited metastable states, or isomers. Of particular interest is a class of isomers found in deformed axially symmetric Nuclei; these isomers are among the longest-lived and have the potential to reach the highest energies. By probing their properties, insights into nuclear structure have been gained. The possibility of stimulated isomer decay may ultimately lead to new forms of energy storage and γ-ray lasers.

H A Weidenmuller - One of the best experts on this subject based on the ideXlab platform.

  • effective field theory for deformed Atomic Nuclei
    Physica Scripta, 2016
    Co-Authors: T Papenbrock, H A Weidenmuller
    Abstract:

    In this paper, we present an effective field theory (EFT) for a model-independent description of deformed Atomic Nuclei. In leading order this approach recovers the well-known results from the collective model by Bohr and Mottelson. When higher-order corrections are computed, the EFT accounts for finer details such as the variation of the moment of inertia with the band head and the small magnitudes of interband E2 transitions. Finally, for rotational bands with a finite spin of the band head, the EFT is equivalent to the theory of a charged particle on the sphere subject to a magnetic monopole field.

  • effective field theory of emergent symmetry breaking in deformed Atomic Nuclei
    Journal of Physics G, 2015
    Co-Authors: T Papenbrock, H A Weidenmuller
    Abstract:

    Spontaneous symmetry breaking in non-relativistic quantum systems has previously been addressed in the framework of effective field theory. Low-lying excitations are constructed from Nambu–Goldstone modes using symmetry arguments only. In this study, we extend that approach to finite systems. The approach is very general. To be specific, however, we consider Atomic Nuclei with intrinsically deformed ground states. The emergent symmetry breaking in such systems requires the introduction of additional degrees of freedom on top of the Nambu–Goldstone modes. Symmetry arguments suffice to construct the low-lying states of the system. Lastly, in deformed Nuclei these are vibrational modes each of which serves as band head of a rotational band.

V. I. Goldanskii - One of the best experts on this subject based on the ideXlab platform.

  • symmetry and pairing energies of Atomic Nuclei
    Nuclear Physics, 2003
    Co-Authors: J. W. Jänecke, T W Odonnell, V. I. Goldanskii
    Abstract:

    Abstract A global investigation of the symmetry and pairing energies of Atomic Nuclei has been undertaken based on excitation energy differences between isobaric analog states. The symmetry energies display pronounced shell effects. An isospin-based shell-model formalism describes the characteristics of Nuclei with neutrons and protons in the same orbits quite well. However, unexpected structures are seen for Nuclei in a region near A ≈84 with N ≈ Z which reflects on quartet ( α -particle-like) structures in agreement with theoretical prediction. A particle–hole formalism has been applied to Nuclei with neutrons and protons in different shell-model orbits. The average neutron–proton interaction depends on the sum of two terms which are proportional to the product of the number of particles and holes and to the number of particles. Good agreement has been achieved with the experimental data except for the heaviest Nuclei.

  • Symmetry energies, pairing energies, and binding energies of Atomic Nuclei
    Exotic Nuclei and Atomic Masses, 2003
    Co-Authors: J. W. Jänecke, T.w. O'donnell, V. I. Goldanskii
    Abstract:

    Energy differences between isobaric analog states were deduced for all Atomic Nuclei. For N = Z Nuclei information is obtained regarding isospin inversion, the T = 0 n–p interaction, and quartet structures. Symmetry and pairing energies over the full range of Atomic Nuclei display very pronounced shell structures.

R F Casten - One of the best experts on this subject based on the ideXlab platform.

  • shape phase transitions and critical point phenomena in Atomic Nuclei
    Nature Physics, 2006
    Co-Authors: R F Casten
    Abstract:

    Atomic Nuclei exhibit phase transitions as a function of the number of their constituent protons and neutrons. These phase transitions are not of the usual thermodynamic type, but rather they are quantum phase transitions in the equilibrium shape and structure of the ground and low-lying states. This realization has sparked a new area of research, focusing on the concept of 'critical-point symmetries', which describe the structure of Nuclei at phase-transitional points. Both macroscopic (geometric or algebraic) and microscopic (shell-model) aspects of these phase transitions and of changes in structure with proton and neutron number in Nuclei are discussed, along with an interpretation in terms of simple Landau theory. Finally, some alternative scenarios and schematic models for different classes of Nuclei based on other simple potentials are briefly summarized.