A proton density bubble in the doubly magic ${}^{34}$Si nucleus

Abstract

Many properties of the atomic nucleus, such as vibrations, rotations and incompressibility, can be interpreted as due to a two component quantum liquid of protons and neutrons. Electron scattering measurements on stable nuclei demonstrate that their central densities are saturated, as for liquid drops. In exotic nuclei near the limits of mass and charge, with large imbalances in their proton and neutron numbers, the possibility of a depleted central density, or a 'bubble' structure, has been discussed in a recurrent manner since the 1970s. Here we report first experimental evidence that points to a depletion of the central density of protons in the short-lived nucleus 34Si. The proton-to-neutron density asymmetry in 34Si offers the possibility to place constraints on the density and isospin dependence of the spin--orbit force-on which nuclear models have disagreed for decades-and on its stabilizing effect towards limits of nuclear existence.

6 pages, 3 figures

References in corpus (8)

• Nuclear magic numbers: new features far from stability
• Systematics of intermediate-energy single-nucleon removal cross sections
• Unveiling the intruder deformed 0${}_2^{+}$ state in ${}^{34}$Si
• Detecting bubbles in exotic nuclei
• Central depression in nuclear density and its consequences for the shell structure of superheavy nuclei
• Beyond-mean-field study of the possible "bubble" structure of 34Si
• Relativistic Hartree-Fock-Bogoliubov model for deformed nuclei
• Spin-orbit splitting in low-j neutron orbits and proton densities in the nuclear interior

Cited by in corpus (14)

• Quenching of single-particle strength from direct reactions with stable and rare-isotope beams
• Central depression in nucleonic densities: Trend analysis in nuclear density-functional-theory approach
• Two-Proton Radioactivity with 2p halo in light mass nuclei A$=$18$-$34
• Bubble nuclei with shape coexistence in even-even isotopes of Hf to Hg
• Imprint of nuclear bubble in nucleon-nucleus diffraction
• Spin-orbit splittings of neutron states in $N=20$ isotones from covariant density functionals and their extensions
• Effect of Finite Binding on the Apparent Spin-Orbit Splitting in Nuclei
• A systematic study of the factors affecting central depletion in nuclei
• Structural properties and decay modes of Z $=$ 122, 120 and 118 superheavy nuclei
• Probing nuclear bubble configuration by proton induced reaction
• Evolution of single-particle structure of silicon isotopes
• The Structure of ${}^{33}$Si and the magicity of the N=20 gap at Z=14
• Bubble nuclei: single-particle versus Coulomb interaction effects
• In-beam $\gamma$-ray spectroscopy of ${}^{32}$Mg via direct reactions