Is the nucleus a "normal" quantum mechanical system?

Speaker

Ani Aprahamian, Notre Dame

Abstract

Everything in the universe is in motion.  In physics, we know that the motion of objects depend on their shapes.   In 1975, the Nobel prize in Physics was awarded to Bohr, Mottelson, and Rainwater for the discovery of the connection between nucleon motion and the emergent collective behavior.  They described nuclei geometrically as a shape and the excited states as oscillations of the nucleus around that shape. The lowest lying shape effecting oscillations or vibrations would be quadrupole in nature, resulting in two types of vibrations in deformed nuclei, one aligned along the symmetry axis and one that is perpendicular to it. Today, over forty years later, the existence and characterization of one of these low-lying vibrations remains an open question in nuclear structure physics. To a large extent, this is due to the lack of sufficient experimental data and somewhat due to what is expected of a vibrational excitation. The absence of these excitations in deformed nuclei call into question why nuclei unlike all other quantum systems, do not exhibit this mode of oscillatory motion and leave open the question regarding nuclei being “normal” quantum mechanical systems.