Vortex Excitations in $\alpha$ Cluster Condensed Nuclei

摘要

We point out an intriguing possibility that there exist topologicalsoliton-like excitations in nuclei with $\alpha$ cluster condensation. Theexcitations are vortices in superfluid, a property possessed by such Bosecondensed nuclei. We show that the vortex-like states possess quantum numbers$J^{P}=n^{(-1)^n}$ and energies $\sim $ several MeV, measured from the groundstate energies of the $n \alpha$ condensed states. We point out actualcandidates, for instance, $2^{+}(3 {MeV})$ for $^{8}$Be, $3^{-}(9.6 {MeV})$ for$^{12}$C, etc, although the topological nature as a vortex is obscure in suchlight nuclei.