Shape transitions in exotic Si and S isotopes and tensor-force-driven Jahn-Teller effect

Abstract

We show how shape transitions in the neutron-rich exotic Si and S isotopes occur in terms of shell-model calculations with a newly constructed Hamiltonian based on V_MU interaction. We first compare the calculated spectroscopic-strength distributions for the proton 0d_5/2,3/2 and 1s_1/2 orbitals with results extracted from a 48Ca(e,e'p) experiment to show the importance of the tensor-force component of the Hamiltonian. Detailed calculations for the excitation energies, B(E2) and two-neutron separation energies for the Si and S isotopes show excellent agreement with experimental data. The potential energy surface exhibits rapid shape transitions along the isotopic chains towards N=28 that are different for Si and S. We explain the results in terms of an intuitive picture involving a Jahn-Teller-type effect that is sensitive to the tensor-force-driven shell evolution. The closed sub-shell nucleus 42Si is a particularly good example of how the tensor-force-driven Jahn-Teller mechanism leads to a strong oblate rather than spherical shape.

6 pages, 6 figures. arXiv admin note: substantial text overlap with arXiv:1201.4077

References in corpus (7)

• Nuclear magic numbers: new features far from stability
• Collapse of the N=28 shell closure in ${}^{42}$Si
• A new effective interaction for $0\hslash \omega$ shell model calculations in the sdpf valence space
• Shell-model study of boron, carbon, nitrogen and oxygen isotopes based on monopole-based-universal interaction
• Orbital dependent nucleonic pairing in the lightest known isotopes of tin
• Energy Density Functional analysis of shape evolution in N=28 isotones
• Measurement of excited states in 40Si and evidence for weakening of the N=28 shell gap

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