Finite-temperature linear response theory based on relativistic Hartree Bogoliubov model with point-coupling interaction

Scientific paper - Original scientific paper

• Author: Ante Ravlić
• Author: Y. F. Niu
• Author: Tamara Nikšić
• Author: Nils Paar
• Author: Peter Ring
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

The finite-temperature linear response theory based on the finite-temperature relativistic Hartree-Bogoliubov (FT-RHB) model is developed in the charge-exchange channel to study the temperature evolution of spin-isospin excitations. Calculations are performed self-consistently with relativistic point-coupling interactions DD-PC1 and DD-PCX. In the charge-exchange channel, the pairing interaction can be split into isovector (T = 1) and isoscalar (T = 0) parts. For the isovector component, the same separable form of the Gogny D1S pairing interaction is used both for the ground-state calculation as well as for the residual interaction, while the strength of the isoscalar pairing in the residual interaction is determined by comparison with experimental data on Gamow-Teller resonance (GTR) and isobaric analog resonance (IAR) centroid energy differences in even-even tin isotopes. The temperature effects are introduced by treating Bogoliubov quasiparticles within a grand-canonical ensemble. Thus, unlike the conventional formulation of the quasiparticle random-phase approximation (QRPA) based on the Bardeen-Cooper-Schrieffer (BCS) basis, our model is formulated within the Hartree- Fock-Bogoliubov (HFB) quasiparticle basis. Implementing a relativistic point-coupling interaction and a separable pairing force allows for the reduction of complicated two-body residual interaction matrix elements, which considerably decreases the dimension of the problem in the coordinate space. The main advantage of this method is to avoid the diagonalization of a large QRPA matrix, especially at finite temperature where the size of configuration space is significantly increased. The implementation of the linear response code is used to study the temperature evolution of IAR, GTR, and spin-dipole resonance (SDR) in even-even tin isotopes in the temperature range T = 0–1.5 MeV.

• Keywords (english): finite-temperature linear response theory; relativistic Hartree Bogoliubov model; point-coupling interaction
• 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. 104, no. 6, 064302
• p-ISSN: 2469-9985
• e-ISSN: 2469-9993
• DOI: https://doi.org/10.1103/PhysRevC.104.064302
• URN:NBN: urn:nbn:hr:217:908720
• Publication: 2021-12
• Project: Number: KK.01.1.1.01.0004; Title (croatian): Provedba vrhunskih istraživanja u sklopu Znanstvenog centra izvrsnosti za kvantne i kompleksne sustave te reprezentacije Liejevih algebri; Title (english): Implementation of top research within the Scientific Center of Excellence for Quantum and Complex Systems, and Representations of Lie Algebras; Acronym: QuantiXLie; Leader: Hrvoje Buljan; Jurisdiction: eu; Funding stream: European Regional Development Fund
• Document URL: https://link.aps.org/doi/10.1103/PhysRevC.104.064302
• Type of resource: Text
• Access conditions: Open access
• Public note: © 2021 American Physical Society. Received 18 August 2021; revised 17 October 2021; accepted 15 November 2021; published 2 December 2021.
• Created on: 2024-09-14 17:04:38