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arXiv · 1905.04142

Is the structure of 42Si understood?

A. Gade·B. A. Brown·J. A. Tostevin·D. Bazin·P. C. Bender·C. M. Campbell·H. L. Crawford·B. Elman·K. W. Kemper·B. Longfellow·E. Lunderberg·D. Rhodes·D. Weisshaar
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Abstract

A more detailed test of the implementation of nuclear forces that drive shell evolution in the pivotal nucleus \nuc{42}{Si} -- going beyond earlier comparisons of excited-state energies -- is important. The two leading shell-model effective interactions, SDPF-MU and SDPF-U-Si, both of which reproduce the low-lying \nuc{42}{Si}($2^+_1$) energy, but whose predictions for other observables differ significantly, are interrogated by the population of states in neutron-rich \nuc{42}{Si} with a one-proton removal reaction from \nuc{43}{P} projectiles at 81~MeV/nucleon. The measured cross sections to the individual \nuc{42}{Si} final states are compared to calculations that combine eikonal reaction dynamics with these shell-model nuclear structure overlaps. The differences in the two shell-model descriptions are examined and linked to predicted low-lying excited $0^+$ states and shape coexistence. Based on the present data, which are in better agreement with the SDPF-MU calculations, the state observed at 2150(13)~keV in \nuc{42}{Si} is proposed to be the ($0^+_2$) level.

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A. Gade, B. A. Brown, J. A. Tostevin, D. Bazin, P. C. Bender, C. M. Campbell, H. L. Crawford, B. Elman, K. W. Kemper, B. Longfellow, E. Lunderberg, D. Rhodes, D. Weisshaar. 2019-05-10. Is the structure of 42Si understood?. https://doi.org/10.1103/physrevlett.122.222501

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