Speaker
Description
Atomic nuclei are strongly-interacting quantum many-body systems and are characterized by a set of good quantum numbers such as angular momentum and parity. Such quantum numbers imply that the nuclear Hamiltonian conserves fundamental symmetries such as invariance by rotation, translation, reflection, etc. Yet, many of the regular patterns observed in the excitation spectrum of nuclei are most conveniently explained if one assumes that nuclei are deformed and do not obey these fundamental symmetries. This spontaneous symmetry breaking is a cornerstone of nuclear theory. While the axial quadrupole shape is the form of nuclear deformation that explains most of the experimental data, higher-order symmetries of the nuclear shape cannot be dismissed. In this talk, I will review why exotic tetrahedral and octahedral shapes could occur in nuclei and what the experimental fingerprints of these modes could be.