Speaker
Description
The crossing of the $2p_{3/2}$ and $1f_{5/2}$ proton s.p. energy levels in neutron-
rich Ni isotopes and the magic character of the atomic number Z=28 in
this isotopic chain is a subject of current interest from both, experimental and theoretical points of view[1,2]. The finite range Simple effective interaction(SEI) is able to reproduce the experimentally observed crossing even without requiring a tensor term. Using SEI, the crossing of the $1f_{5/2}$ and $2p_{3/2}$ s.p. proton levels in the isotopic chain of Ni and the spin inversion in the ground-state of Cu-isotopes are found to be a function of nuclear matter(NM) incompressibility. The role of the incompressibility is also noticed in the study of sd- level splitting in Ca isotopic chain using the SEI model. Experimental studies[3,4] establish that the proton $2s_{1/2}$ and $1d_{3/2}$ s.p. levels invert going from $^{40}Ca$ to $^{48}Ca$. However, the observed proton gaps between the $1h_{11/2}$ and $1g_{7/2}$ shells in Sn and Sb isotopic chain, and the neutron gaps between the $1i_{13/2}$ and $1h_{9/2}$ shells in N=82 isotones[5] require explicit consideration of a tensor part with SEI as the central contribution is not enough to initiate the required level splittings. In this work, we will analyze the observed proton and neutron single-particle energy gaps in Sn and N=82 isotopic and isotonic chains respectively by adding a short-range tensor force to SEI within the Quasi-local Density Functional Theory (QLDFT) formalism and compared the results with the available experimental data[5] as well as with the predictions of other mean field models such as the SIII and SAMI-T Skyrme forces and the D1MTd Gogny interaction.
References
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119, 192501 (2017).
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Lett. 118, 242502 (2017).
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210 (1976).
[4] C. A. Ogilvie et al., Nucl. Phys. A 465, 445 (1987).
[5] J P Schiffer, S J Freeman , J A Caggiano, C Deibel, A Heinz , et al.,
Phys. Rev. Lett. 92, 162501(2004).
