Finite-temperature effects in magnetic dipole transitions

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 effects in electromagnetic transitions in nuclei contribute to many aspects of nuclear structure and astrophysically relevant nuclear reactions. While electric dipole transitions have already been extensively studied, the temperature sensitivity of magnetic transitions remains largely unknown. This work comprises the study of isovector magnetic dipole excitations (𝑀⁢1) occurring between spin-orbit (SO) partner states using the recently developed self-consistent finite-temperature relativistic quasiparticle random-phase approximation (FT-RQRPA) in the temperature range from 𝑇= 0 to 2 MeV. The 𝑀⁢1 strength distributions of 40−60Ca and 100−140Sn isotopic chains exhibit a considerable temperature dependence. The 𝑀⁢1 strength peaks shift significantly towards the lower energies due to the decrease in SO splitting energies and weakening of the residual interaction, especially above the critical temperatures where the pairing correlations vanish. By exploring the relevant two-quasiparticle configurations contributing to the 𝑀⁢1 strength of closed- and open-shell nuclei, new proton and neutron excitation channels between SO partners are observed in low- and high-energy regions due to the thermal unblocking effects around the Fermi level. At higher temperatures, we have noticed an interesting result in 40,60Ca nuclei, the appearance of 𝑀⁢1 excitations, which are forbidden at zero temperature due to fully occupied (or fully vacant) spin-orbit partner states.

• Keywords (english): finite-temperature effects; magnetic dipole transitions
• 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. 2, 024305
• p-ISSN: 2469-9985
• e-ISSN: 2469-9993
• DOI: https://doi.org/10.1103/PhysRevC.109.024305
• URN:NBN: urn:nbn:hr:217:241410
• 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.109.024305
• Type of resource: Text
• Access conditions: Open access
• Public note: © 2024 American Physical Society. Received 13 October 2023. Accepted 22 January 2024. Published 6 February 2024.
• Created on: 2024-07-29 12:36:21