Electric dipole transitions in the relativistic quasiparticle random-phase approximation at finite temperature

Scientific paper - Original scientific paper

• Author: Amandeep Kaur
• Author: Esra Yüksel
• Author: Nils Paar
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

Finite temperature results in various effects on the properties of nuclear structure and excitations of relevance for nuclear processes in hot stellar environments. Here, we introduce the self-consistent finite temperature relativistic quasiparticle random phase approximation (FT-RQRPA) based on relativistic energy density functional with point coupling interaction for describing the temperature effects in electric dipole (𝐸⁢1) transitions. We perform a study of 𝐸⁢1 excitations in the temperature range 𝑇=0–2 MeV for the selected closed- and open-shell nuclei ranging from 40Ca to 60Ca and 100Sn to 140Sn by including both thermal and pairing effects. The isovector giant dipole resonance strength is slightly modified for the considered range of temperature, while new low-energy peaks emerge for 𝐸<12 MeV with non-negligible strength in neutron-rich nuclei at high temperatures. The analysis of relevant two-quasiparticle configurations discloses how new excitation channels open due to thermal unblocking of states at finite temperature. The study also examines the isospin and temperature dependence of electric dipole polarizability (𝛼𝐷), resulting in systematic increase in the values of 𝛼𝐷 with increasing temperature, with a more pronounced effect observed in neutron-rich nuclei. The FT-RQRPA introduced in this work will open perspectives for microscopic calculation of 𝛾-ray strength functions at finite temperatures relevant for nuclear reaction studies.

• Keywords (english): electric dipole transitions; finite temperature
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physical Review C
• Numbering: vol. 109, no. 1, 014314
• p-ISSN: 2469-9985
• e-ISSN: 2469-9993
• DOI: https://doi.org/10.1103/PhysRevC.109.014314
• URN:NBN: urn:nbn:hr:217:054511
• Publication: 2024
• Project: Number: IP-2022-10-7773; Title (croatian): Relativistička nuklearna višečestična teorija u doba opažanja raznovrsnih signala; Title (english): Relativistic nuclear many-body theory in the multimessenger observation era; Acronym: RELANUM; Leader: Nils Paar; Jurisdiction: Croatia; Funding stream: Research Projects
• Document URL: https://link.aps.org/doi/10.1103/PhysRevC.109.014314
• Type of resource: Text
• Access conditions: Open access
• Public note: © 2024 American Physical Society. Received 2 October 2023. Accepted 22 December 2023. Published 11 January 2024.
• Created on: 2024-07-31 08:10:24