Bubbles in ${}^{34}$Si and ${}^{22}$O?

Abstract

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

Comments: 9 figures