Seminar: Exotic Nuclei near the Neutron Drip Line: Nuclear Structure Effects in Elemental Abundances in Explosive Nucleosynthesis

We are made of, and surrounded by, elements such as carbon, oxygen, iron, and even gold, yet the origin of the heaviest elements remains an open question in nuclear astrophysics. The rapid neutron capture process (r-process) is believed to be responsible for producing more than half of the elements heavier than iron; however, accurate predictions of r-process abundances are hindered by large uncertainties in nuclear physics inputs far from stability.

Nuclei away from the valley of stability, particularly those near the neutron drip line, challenge our conventional understanding of nuclear structure. Many such nuclei exhibit exotic features, including extended matter distributions in halo nuclei such as 19C, 31Ne, 37Mg, as well as central density depletions in so-called bubble nuclei like 20N. These unusual density profiles can significantly modify reaction dynamics, raising the question of how strongly they influence stellar reaction rates and, in turn, nucleosynthesis and solar r-process abundance patterns.

In this talk, I will present a systematic investigation of the impact of exotic nuclear structure on neutron capture and photodisintegration rates and assess how these effects propagate into abundance predictions in explosive nucleosynthesis scenarios.

I will first demonstrate the influence of exotic halo and bubble nuclei, such as 19C and 20N, on abundance evolution in a neutron-rich C-N-O reaction network under supernova-like conditions. I then extend the analysis to medium-mass exotic nuclei in the A ~ 20 - 40 mass region and explore their impact on r-process abundance patterns across a range of astrophysical trajectories, including binary neutron star merger ejecta, using large-scale reaction network calculations. The results demonstrate that nuclear structure effects can alter the final abundance distributions under specific astrophysical conditions, emphasizing the importance of incorporating proper nuclear structure inputs in r-process modeling.