Multidimensionally-constrained relativistic mean- field study of spontaneous fission: Coupling between shape and pairing degrees of freedom

Znanstveni rad - Izvorni znanstveni rad

• Autor: Jie Zhao
• Autor: Bing-nan Lu
• Autor: Tamara Nikšić; MBZ: 234533
• Autor: Dario Vretenar; MBZ: 9570
• Autor: Shan-Gui Zhou
• Autorova ustanova: Sveučilište u Zagrebu; Prirodoslovno-matematički fakultet; (Fizički odsjek)
• Znanstveno / umjetničko područje, polje i grana: PRIRODNE ZNANOSTI; Fizika

Sažetak (engleski)

Background: Studies of fission dynamics, based on nuclear energy density functionals, have shown that the coupling between shape and pairing degrees of freedom has a pronounced effect on the nonperturbative collective inertia and, therefore, on dynamic (least-action) spontaneous fission paths and half-lives. Purpose: The aim is to analyze the effects of particle-number fluctuation degrees of freedom on symmetric and asymmetric spontaneous fission (SF) dynamics, and to compare the findings with the results of recent studies based on the self-consistent Hartree-Fock-Bogoliubov (HFB) method. Methods: Collective potentials and nonperturbative cranking collective inertia tensors are calculated using the multidimensionally- constrained relativistic-mean-field (MDC-RMF) model. Pairing correlations are treated in the BCS approximation using a separable pairing force of finite range. Pairing fluctuations are included as a collective variable using a constraint on particle-number dispersion. Fission paths are determined with the dynamic programming method by minimizing the action in multidimensional collective spaces. Results: The dynamics of spontaneous fission of Fm264 and Fm250 are explored. Fission paths, action integrals, and corresponding half-lives computed in the three-dimensional collective space of shape and pairing coordinates, using the relativistic functional DD-PC1 and a separable pairing force of finite range, are compared with results obtained without pairing fluctuations. Results for Fm264 are also discussed in relation with those recently obtained using the HFB model. Conclusions: The inclusion of pairing correlations in the space of collective coordinates favors axially symmetric shapes along the dynamic path of the fissioning system, amplifies pairing as the path traverses the fission barriers, significantly reduces the action integral, and shortens the corresponding SF half-life.

• Ključne riječi (engleski): fission; nuclear energy density functional
• 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. 93, br. 4, 044315
• p-ISSN: 2469-9985
• e-ISSN: 2469-9993
• DOI: https://doi.org/10.1103/PhysRevC.93.044315
• URN:NBN: urn:nbn:hr:217:221722
• Datum objave publikacije: 2016
• Projekt: Šifra: IP-2014-09-9159; Naziv (hrvatski): Struktura i dinamika egzotičnih femto-sustava; Kratica: STRUDEF; Voditelj: Nils Paar; Pravna nadležnost: Hrvatska; Financijer: HRZZ; Linija financiranja: IP
• URL dokumenta: https://journals.aps.org/prc/abstract/10.1103/PhysRevC.93.044315
• Vrsta resursa: Tekst
• Prava pristupa: Otvoreni pristup
• Javna napomena: © 2016 American Physical Society. Received 29 February 2016; published 15 April 2016.
• Datum i vrijeme pohrane: 2020-02-23 14:07:13