Liquid drop model and quantum pressure resisting noncompact nuclear geometries

The importance of quantum effects for exotic nuclear shapes is discussed. Based on an example of a sheet of nuclear matter of infinite lateral dimensions but finite thickness, it is shown that the quantization of states in momentum space, resulting from the confinement of the nucleonic motion in the conjugate geometrical space, generates a pressure resisting such a confinement and, consequently, restoring forces driving the systems toward compact geometries. In the liquid-drop model, these quantum effects are implicitly included in the surface energy term, via a choice of interaction parameters, an approximation that has been found valid for compact shapes, but has not yet been scrutinized for exotic shapes.