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Colloquium, Rutgers, Sept. 23, 2009
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| Quantum Phase Transitions in Finite Nuclei and Nuclear Structural Evolution | ||
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Richard F.
Casten
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| A new development in the understanding of the evolution of the structure of atomic nuclei with proton and neutron number centers around the concept of Quantum Phase Transitions (QPTs), that is, phase transitions in the equilibrium (ground state) structure (shape). This was initiated with high sensitivity studies of beta decay in the Sm region and has developed into a major area of research worldwide. The QPT concept allows a simple classification of structural types based on Landau theory of phase transitional behavior. The description of nuclei in shape transitional regions has long been considered one of the most challenging problems in nuclear structure theory. Therefore a key, and surprising, advance was the proposal, and empirical validation, of extremely simple, parameter-free, models for nuclei at the critical point. Called Critical Point Symmetries (CPSs), they have spawned a new generation of geometrical descriptions of nuclei. This talk will introduce these ideas, discuss the early work, and the most recent extensions, including the first non-trivial example of a nuclear Quasi-Dynamical Symmetry. |
