Superdeformed and hyperdeformed states in 56Ni.

Abstract

Resonances in $^{12}\mathrm{C}$${+}^{12}$C and $^{24}\mathrm{Mg}$${+}^{24}$Mg scattering have been associated with hyperdeformed configurations in the harmonic oscillator shell model and the alpha-cluster model. Resonances in $^{28}\mathrm{Si}$${+}^{28}$Si scattering do not seem to fit into this picture so well. We present alpha-cluster model calculations for superdeformed and hyperdeformed states in $^{56}\mathrm{Ni}$. One configuration identified in our calculations corresponds to a 2:1 harmonic oscillator configuration. The others are more complex; however, none gives a totally satisfactory explanation of the $^{28}\mathrm{Si}$${+}^{28}$Si resonances.