The possibility that an unconventional depletion (referred to as a “bubble”) occurs in the center of the charge density distribution of certain atomic nuclei, due to a purely quantum mechanical effect, has attracted theoretical and experimental attention in recent years.
We have performed the first ab initio calculations of the unstable 34Si nucleus that appears to be the best candidate to display such an exotic nuclear phenomenon. The occurrence of a bubble structure in the charge distribution of 34Si is convincingly established and anticipated to leave a visible fingerprint in a potential future electron scattering experiment. Furthermore, a clear correlation is established between the occurrence of the bubble structure in 34Si and (i) the weakening of the 1/2–-3/2– energy splitting in the spectrum of 35Si as compared to 37S as well as (ii) the change of root-mean-square charge radius between 36S and 34Si. While the former correlation is a confirmation of a recent (d,p) experiment, the latter result acts as a strong motivation to measure the root-mean-square charge radius of 34Si in the near future.