Axially deformed relativistic quasiparticle random-phase approximation based on point-coupling interactions

Znanstveni rad - Izvorni znanstveni rad

• Autor: Ante Ravlić
• Autor: Tamara Nikšić
• Autor: Y. F. Niu
• Autor: Peter Ring
• Autor: Nils Paar
• Autorova ustanova: Sveučilište u Zagrebu; Prirodoslovno-matematički fakultet; (Fizički odsjek)
• Znanstveno / umjetničko područje, polje i grana: PRIRODNE ZNANOSTI; Fizika

Sažetak (engleski)

Collective nuclear excitations, like giant resonances, are sensitive to nuclear deformation, as evidenced by alterations in their excitation energies and transition strength distributions. A common theoretical framework to study these collective modes, the random-phase approximation (RPA), has to deal with large dimensions spanned by all possible particle-hole configurations satisfying certain symmetries. It is the aim of this work to establish a new theoretical framework to study the impact of deformation on spin-isospin excitations, that is able to provide fast and reliable solutions of the RPA equations. The nuclear ground state is determined with the axially deformed relativistic Hartree-Bogoliubov (RHB) model based on relativistic point-coupling energy density functionals (EDFs). To study the excitations in the charge-exchange channel, an axially deformed proton-neutron relativistic quasiparticle RPA (pnRQRPA) is developed in the linear response approach. After benchmarking the axially deformed pnRQRPA in the spherical limit, a study of spin-isospin excitations including Fermi, Gamow-Teller (GT), and spin-dipole (SD) is performed for selected pf -shell nuclei. For GT transitions, it is demonstrated that deformation leads to a considerable fragmentation of the strength function. A mechanism inducing the fragmentation is studied by decomposing the total strength to different projections of total angular momentum K and constraining the nuclear shape to either spherical, prolate, or oblate. A similar fragmentation is also observed for SD transitions, although somewhat moderated by the complex structure of these transitions, while, as expected, the Fermi strength is almost shape independent. The axially deformed pnRQRPA introduced in this work open perspectives for the future studies of deformation effects on astrophysically relevant weak interaction processes, in particular beta decay and electron capture.

• Ključne riječi (engleski): point-coupling interactions; axially deformed pnRQRPA
• Jezik: engleski
• Vrsta publikacije: Znanstveni rad - Izvorni znanstveni rad
• Status objave: Objavljen
• Vrsta recenzije: Recenziran - međunarodna recenzija
• Verzija publikacije: Objavljena verzija rada (izdavačev PDF)
• Naslov časopisa: Physical Review C
• Brojčani podaci: vol. 110, br. 2, 024323
• p-ISSN: 2469-9985
• e-ISSN: 2469-9993
• DOI: https://doi.org/10.1103/PhysRevC.110.024323
• URN:NBN: urn:nbn:hr:217:923769
• Datum objave publikacije: 2024
• Projekt: Šifra: IP-2022-10-7773; Naziv (hrvatski): Relativistička nuklearna višečestična teorija u doba opažanja raznovrsnih signala; Naziv (engleski): Relativistic nuclear many-body theory in the multimessenger observation era; Kratica: RELANUM; Voditelj: Nils Paar; Pravna nadležnost: Hrvatska; Financijer: Hrvatska zaklada za znanost; Linija financiranja: Research Projects
• Projekt: Šifra: KK.01.1.1.01.0004; Naziv (hrvatski): Provedba vrhunskih istraživanja u sklopu Znanstvenog centra izvrsnosti za kvantne i kompleksne sustave te reprezentacije Liejevih algebri; Naziv (engleski): Implementation of top research within the Scientific Center of Excellence for Quantum and Complex Systems, and Representations of Lie Algebras; Kratica: QuantiXLie; Voditelj: Hrvoje Buljan; Pravna nadležnost: eu; Financijer: Europska komisija; Linija financiranja: European Regional Development Fund
• URL dokumenta: https://link.aps.org/doi/10.1103/PhysRevC.110.024323
• Vrsta resursa: Tekst
• Prava pristupa: Otvoreni pristup
• Javna napomena: © 2024 American Physical Society. Received 22 April 2024; accepted 13 August 2024; published 29 August 2024.
• Datum i vrijeme pohrane: 2024-09-12 12:40:44