2025/10/06 by Amandeep Kaur, Esra Yüksel, Ν. Paar · 1 voice
Physics and Astronomy · Engineering · #Nuclear physics research studies #Nuclear reactor physics and engineering #Laser-Plasma Interactions and Diagnostics
paper · doi:10.1103/3t7h-nds7
openalex publication_date 2025/10/06 · openalex created_date 2025/11/28 · openalex updated_date 2026/08/01
At finite temperatures, nuclear excitations are significantly modified, most notably through the emergence of additional low-energy dipole strength, which can critically impact astrophysical reaction rates. Ongoing fusion-evaporation experiments on Ni isotopes provide a unique opportunity to investigate the hot pygmy dipole strength (HPDS), underscoring the need for reliable theoretical predictions and a comprehensive understanding of this emerging phenomenon. In this work, the HPDS is investigated in Ni isotopes from N=Z to neutron-rich systems (56--70Ni) over a temperature range of T=0--2 MeV using the finite-temperature relativistic quasiparticle random-phase approximation (FT-RQRPA). In neutron-rich Ni isotopes, the pygmy dipole strength at higher temperatures exceeds by up to 2.5 times its value observed at zero temperature. In contrast, near N\ensuremath≈Z, isotopes show negligible low-energy dipole strength at T=0 MeV but develop a pronounced HPDS as the temperature increases. Predicted E1 energy-weighted strength (SEWS) and cumulative B(E1) values for HPDS are presented across the Ni isotopic chain for various low-energy intervals and temperatures, providing essential benchmarks to support and guide experimental studies.