Is the structure of 42Si understood?

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.

arXiv commentaccepted in Physical Review Letters

References in corpus (10)

• Collapse of the N=28 shell closure in ${}^{42}$Si
• Shape transitions in exotic Si and S isotopes and tensor-force-driven Jahn-Teller effect
• A new effective interaction for $0\hslash \omega$ shell model calculations in the sdpf valence space
• The merging of the islands of inversion at N=20 and N=28
• Systematics of intermediate-energy single-nucleon removal cross sections
• Well-developed deformation in 42Si
• Evolution of the N=28 shell closure: a test bench for nuclear forces
• Shell structure at N=28 near the dripline: spectroscopy of ${}^{42}$Si, ${}^{43}$P and ${}^{44}$S
• New isotope 44Si and systematics of the production cross sections of the most neutron-rich nuclei
• Two-proton removal from ${}^{44}$S and the structure of ${}^{42}$Si

Cited by in corpus (10)

• The Neutron-Rich Edge of the Nuclear Landscape. Experiment and Theory
• Updated systematics of intermediate-energy single-nucleon removal cross sections
• UCGretina GEANT4 Simulation of the GRETINA Gamma-Ray Energy Tracking Array
• Examining the $N$ = 28 shell closure through high-precision mass measurements of ${}^{46-48}$Ar
• Inverse-kinematics proton scattering from ${}^{42,44}$S, ${}^{41,43}$P and the collapse of the $N=28$ major shell closure
• Microscopic study of the Shell Structure evolution in isotopes of light to middle mass range Nuclides
• Shell structure of ${}^{43}$S and collapse of the $N=28$ shell closure
• Structure of ${}^{43}$P and ${}^{42}$Si in a two-level shape-coexistence model
• Weakening of $N=28$ shell gap and the nature of $0_2^{+}$ states
• Determination of proton and neutron contributions to the $0_{g.s.}^{+}\to 2_1^{+}$ excitations in ${}^{42}$Si and ${}^{44}$S using inelastic proton scattering in inverse kinematics and intermediate energy Coulomb excitation