Speaker
Description
Electromagnetic probes provide a uniquely clean and selective window into the internal structure of atomic nuclei. Real photon beams, in particular, couple directly to the charge and current distributions without introducing strong interaction distortions, thereby enabling model independent spectroscopic investigations of nuclear excitations. Their well defined spin selectivity, polarization control, and high sensitivity to transition strengths make them ideally suited for isolating electric and magnetic dipole modes across a broad excitation energy range. This capability is especially powerful for mapping dipole strength distributions from a few MeV up to and beyond the particle emission threshold, where the interplay between single particle motion and collective dynamics gives rise to a variety of nuclear phenomena, the precise characterization of which provides stringent constraints on nuclear structure models and has direct implications for astrophysical reaction rates and nucleosynthesis pathways. In this talk, I will present recent results from nuclear resonance fluorescence measurements performed with quasi monochromatic, highly polarized photon beams at the High Intensity gamma ray Source (HI$\gamma$S) at the Triangle Universities Nuclear Laboratory. Emphasis will be placed on high resolution determinations of dipole strength distributions, identification of fine structure and multipole character through polarization asymmetries and angular distributions, and the extraction of reduced transition probabilities and branching ratios. The experimental results will be confronted with state-of-the-art theoretical calculations and compared with complementary data from hadron induced reactions, to highlight the distinct selectivity, interpretive clarity, and quantitative rigor afforded by the photonuclear approach.
| Contribution category | Experiment |
|---|---|
| Presenter status | Faculty/Staff |