The study of nuclear interactions and properties from the underlying theory of Quantum Chromodynamics (QCD) represents a central goal in nuclear physics research. At low energies, however, QCD becomes non-linear and strongly interacting, eluding first-principle pencil-and-paper calculations of nuclear properties. An important aspect of nuclear physics at low energy is the physics associated with weakly bound systems. Some properties of such systems are universally shared across atomic, nuclear and particle physics. The effective field theory (EFT) formulation allows for systematic calculations of nuclear properties that are deeply rooted in QCD. EFT allows reliable error estimates in calculations that are otherwise difficult to estimate in phenomenological approaches. In the supported research work, EFT for few-body systems involving electromagnetic radiation would be constructed. Key reactions involving light nuclei that are relevant in Big Bang Nucleosynthesis and stellar burning would be studied. Some of these reactions play an important role in interpreting experimental results probing physics beyond the Standard Model of particle physics. The proposed work would also introduce new model-independent tools with reliable error estimates to study halo nuclei. These nuclei are described as a tightly bound core with usually one or two valence neutrons forming a halo. This research ties in with planned major U.S. investment in rare isotope beam experiments.
Broader impacts of the research include training of physics graduate students in numerical and analytical work for an academic or industry career benefiting society. Results from this research work would be incorporated in a graduate course. Atomic physics research would also be affected by this study of weakly bound few-body systems due to the universality described above. Atomic systems with large scattering lengths form an active field of theoretical and experimental research.
