Speaker
Description
The electromagnetic dipole response of atomic nuclei is fundamental for understanding nuclear structure and reaction dynamics. Measurements of photon strength functions (PSFs) have revealed phenomena such as Low-Energy Enhancement, significantly affecting astrophysical reaction rates relevant to nucleosynthesis.
To investigate the shape of the PSF and the observed excitation modes below S$_{n}$, the sub-barrier $^{89}$Y(p,$\gamma$)$^{90}$Zr radiative capture reaction was performed at four (4) incident proton beam energies. The resulting $\gamma$ decays were measured using Gamma-Ray Energy Tracking In-beam Nuclear Array (GRETINA) [1]. By applying the Shape Method [2], the shape of the PSF will be extracted for $\gamma$-ray energies below S$_{n}$. This analysis aims to provide new constraints on the shape of PSF in $^{90}$Zr and to shed light on the LEE's underlying physical mechanisms at the lowest accessible energies.
In this talk, preliminary results on the shape of $^{90}$Zr PSF obtained from radiative proton capture using the Shape Method will be discussed.
[1] S. Paschalis, I.Y. Lee, A.O. Macchiavelli et al., Nucl. Instrum. Methods A 709, 44 (2013).
[2] M. Wiedeking, M. Guttormsen, A.C. Larsen et al., Phys. Rev. C 104, 014311 (2021).
Research supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Contracts No. DE-AC02-05CH11231 and by the US Nuclear Data Program.