Search

Samples of the spectrum of the 36Ar nucleus are known in different energy windows. In addition to the ground state region (GS), the superdeformed (SD) state is observed, too, and there is a good candidate for the hyperdeformed (HD) one, as well. They are populated in different reactions. We intend to describe the gross features of the spectra of different energies, deformations and reactions in a unified way. We apply the multiconfigurational dynamical symmetry (MUSY). The SU(3) quantum numbers of the shape isomers from previous studies pave the way for this description. The MUSY reproduces the gross features of the spectra to a reasonable approximation. The energy spectrum of the three valleys (GS, SD, HD) indicates that the multiconfigurational symmetry is valid to a good approximation, and different cluster configurations coexist in the shape isomers., 13 pages, 5 figures

Background: Aspects of the nuclear structure of light α-conjugate nuclei have long been associated with nuclear clustering based on α particles and heavier α-conjugate systems such as C12 and O16. Such structures are associated with strong deformation corresponding to superdeformed or even hyperdeformed bands. Superdeformed bands have been identified in Ca40 and neighboring nuclei and find good description within shell model, mean-field, and α-cluster models. The utility of the α-cluster description may be probed further by extending such studies to more challenging cases comprising lighter α-conjugate nuclei such as Mg24, Si28, and S32. Purpose: The purpose of this study is to look for the number and energy of isoscalar 0+ states in Si28. These states are the potential bandheads for superdeformed bands in Si28 corresponding to the exotic structures of Si28. Of particular interest is locating the 0+ bandhead of the previously identified superdeformed band in Si28. Methods: α-particle inelastic scattering from a Sinat target at very forward angles including 0 has been performed at the iThemba Laboratory for Accelerator-Based Sciences in South Africa. Scattered particles corresponding to the excitation energy region of 6 to 14 MeV were momentum-analysed in the K600 magnetic spectrometer and detected at the focal plane using two multiwire drift chambers and two plastic scintillators. Results: Several 0+ states have been identified above 9 MeV in Si28. A newly identified 9.71 MeV 0+ state is a strong candidate for the bandhead of the previously discussed superdeformed band. The multichannel dynamical symmetry of the semimicroscopic algebraic model predicts the spectrum of the excited 0+ states. The theoretical prediction is in good agreement with the experimental finding, supporting the assignment of the 9.71-MeV state as the bandhead of a superdeformed band. Conclusion: Excited isoscalar 0+ states in Si28 have been identified. The number of states observed in the present experiment shows good agreement with the prediction of the multichannel dynamical symmetry.

Aspects of nuclear structure in alpha-conjugate nuclei have long been associated with alpha clustering, including the existence of superdeformed bands. In this paper, an alpha-particle inelastic scattering experiment investigating the location of $0^+$ states in $^{28}$Si is reported in an attempt to locate possible cluster states. The results are compared to a semi-microscopic model which shows good agreement with the data, and supports the assignment of a newly discovered $0^+$ state as the band-head of a previously observed superdeformed band in $^{28}$Si, Comment: 6 figures, 8 pages, updated to fix broken figure placement, updated again to fix a couple of typos; final update