Bubble nuclei are characterized by a depletion of their central density. Their existence is examined within three different theoretical frameworks: the shell model and nonrelativistic and relativistic microscopic mean-field approaches. We analyze ${}^{34}\mathrm{Si}$ and ${}^{22}\mathrm{O}$ as possible candidates for proton and neutron bubble nuclei, respectively. In the case of ${}^{22}\mathrm{O}$, we observe a significant model dependence, thereby calling into question the bubble structure of ${}^{22}\mathrm{O}$. In contrast, an overall agreement among the models is obtained for ${}^{34}\mathrm{Si}$. Indeed, all models predict a central proton density depletion of about 40% and a central charge density depletion of 25%–30%. This result provides strong evidence in favor of a proton bubble in ${}^{34}\mathrm{Si}$.

• Received 22 September 2008

DOI:https://doi.org/10.1103/PhysRevC.79.034318