Atomic Nuclei: Many-Body Open Quantum Systems
The physics of Open Quantum Systems has attracted a lot of attention in many fields of physics. In atomic nuclei, the "openness" of the system manifests itself by the coupling to the many-body continuum representing various decay, scattering, and reaction channels. Due to the presence of particle thresholds, atomic nuclei form a network of correlated fermionic systems interconnected via reaction channels.
The space of states that are unbound to particle emission may have significant impact on spectroscopic properties of nuclei. Moving towards the drip lines, the coupling to the particle continuum becomes systematically more important, eventually playing a dominant role in determining structure. Theories of such nuclei need to take these additional ingredients and effects into account.
Many aspects of nuclei at the limits of the nuclear landscape, such as those related to the proximity of reaction channels, are generic and are currently explored in other open systems: molecules in strong external fields, quantum dots and wires and other solid-state microdevices, crystals in laser fields, and microwave cavities. Radioactive nuclear beam experimentation will answer crucial questions pertaining to all open quantum systems: What are their properties around the lowest energies where the reactions become energetically allowed (reaction thresholds)? What is the origin of states in which nuclei resemble groupings of nucleons into well-defined clusters, especially those of astrophysical importance? What should be the most important steps in developing the theory that will treat nuclear structure and reactions consistently? This presentation will address some of the research challenges pertaining to the interplay between nuclear openness, shell structure, and many-body correlations.
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