Effective proton-neutron interaction near the drip line from unbound states in ²⁵̛ ²⁶ F

Background: Odd-odd nuclei, around doubly closed shells, have been extensively used to study proton-neutron interactions. However, the evolution of these interactions as a function of the binding energy, ultimately when nuclei become unbound, is poorly known. The ²⁶F nucleus, composed of a deeply bo...

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Autor: Fraile Prieto, Luis Mario
Formato: artículo
Fecha de publicación:2019
País:España
Recursos:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/5952
Acesso em linha:https://hdl.handle.net/20.500.14352/5952
Access Level:acceso abierto
Palavra-chave:539.1
Nuclear-forces
Rich nuclei
Detector
Electricidad
Electrónica (Física)
Física nuclear
2202.03 Electricidad
2207 Física Atómica y Nuclear
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oai_identifier_str oai:docta.ucm.es:20.500.14352/5952
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spelling Effective proton-neutron interaction near the drip line from unbound states in ²⁵̛ ²⁶ FFraile Prieto, Luis Mario539.1Nuclear-forcesRich nucleiDetectorElectricidadElectrónica (Física)Física nuclear2202.03 Electricidad2207 Física Atómica y NuclearBackground: Odd-odd nuclei, around doubly closed shells, have been extensively used to study proton-neutron interactions. However, the evolution of these interactions as a function of the binding energy, ultimately when nuclei become unbound, is poorly known. The ²⁶F nucleus, composed of a deeply bound π 0d_(5/2) proton and an unbound ν0d_(3/2) neutron on top of an ²⁴O core, is particularly adapted for this purpose. The coupling of this proton and neutron results in a J^π= 1₁⁺ - 4₁⁺ multiplet, whose energies must be determined to study the influence of the proximity of the continuum on the corresponding proton-neutron interaction. The J^π = 1₁⁺, 2₁⁺, 4₁⁺ bound states have been determined, and only a clear identification of the J^π = 3₁⁺ is missing. Purpose: We wish to complete the study of the J^π = 1₁⁺ - 4₁⁺multiplet in ²⁶F, by studying the energy and width of the J^π = 3₁⁺unbound state. The method was first validated by the study of unbound states in ²⁵, for which resonances were already observed in a previous experiment. Method: Radioactive beams of ²⁶Ne and ²⁷Ne, produced at about 440AMeV by the fragment separator at the GSI facility were used to populate unbound states in ²⁵F and ²⁶F via one-proton knockout reactions on a CH₂ target, located at the object focal point of the R³B/LAND setup. The detection of emitted. γ and neutrons, added to the reconstruction of the momentum vector of the A - 1 nuclei, allowed the determination of the energy of three unbound states in ²⁵F and two in ²⁶F. Results: Based on its width and decay properties, the first unbound state in ²⁵F, at the relative energy of 49(9) keV, is proposed to be a J^π = 1/ 2ˉ arising from a p_(1/2) proton- hole state. In ²⁶F, the first resonance at 323(33) keV is proposed to be the J^π = 3₁⁺ member of the J^π = 1₁⁺- 4₁⁺multiplet. Energies of observed states in ²⁵ʼ²⁶F have been compared to calculations using the independent-particle shell model, a phenomenological shell model, and the ab initio valence-space in-medium similarity renormalization group method. Conclusions: The deduced effective proton- neutron interaction is weakened by about 30-40% in comparison to the models, pointing to the need for implementing the role of the continuum in theoretical descriptions or to a wrong determination of the atomic mass of ²⁶F.American Physical SocietyUniversidad Complutense de Madrid20192019-11-0820192019-11-08journal articlehttp://purl.org/coar/resource_type/c_6501info:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/20.500.14352/5952reponame:Docta Complutenseinstname:Universidad Complutense de Madrid (UCM)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2info:eu-repo/semantics/openAccessoai:docta.ucm.es:20.500.14352/59522026-06-02T12:44:21Z
dc.title.none.fl_str_mv Effective proton-neutron interaction near the drip line from unbound states in ²⁵̛ ²⁶ F
title Effective proton-neutron interaction near the drip line from unbound states in ²⁵̛ ²⁶ F
spellingShingle Effective proton-neutron interaction near the drip line from unbound states in ²⁵̛ ²⁶ F
Fraile Prieto, Luis Mario
539.1
Nuclear-forces
Rich nuclei
Detector
Electricidad
Electrónica (Física)
Física nuclear
2202.03 Electricidad
2207 Física Atómica y Nuclear
title_short Effective proton-neutron interaction near the drip line from unbound states in ²⁵̛ ²⁶ F
title_full Effective proton-neutron interaction near the drip line from unbound states in ²⁵̛ ²⁶ F
title_fullStr Effective proton-neutron interaction near the drip line from unbound states in ²⁵̛ ²⁶ F
title_full_unstemmed Effective proton-neutron interaction near the drip line from unbound states in ²⁵̛ ²⁶ F
title_sort Effective proton-neutron interaction near the drip line from unbound states in ²⁵̛ ²⁶ F
dc.creator.none.fl_str_mv Fraile Prieto, Luis Mario
author Fraile Prieto, Luis Mario
author_facet Fraile Prieto, Luis Mario
author_role author
dc.contributor.none.fl_str_mv Universidad Complutense de Madrid
dc.subject.none.fl_str_mv 539.1
Nuclear-forces
Rich nuclei
Detector
Electricidad
Electrónica (Física)
Física nuclear
2202.03 Electricidad
2207 Física Atómica y Nuclear
topic 539.1
Nuclear-forces
Rich nuclei
Detector
Electricidad
Electrónica (Física)
Física nuclear
2202.03 Electricidad
2207 Física Atómica y Nuclear
description Background: Odd-odd nuclei, around doubly closed shells, have been extensively used to study proton-neutron interactions. However, the evolution of these interactions as a function of the binding energy, ultimately when nuclei become unbound, is poorly known. The ²⁶F nucleus, composed of a deeply bound π 0d_(5/2) proton and an unbound ν0d_(3/2) neutron on top of an ²⁴O core, is particularly adapted for this purpose. The coupling of this proton and neutron results in a J^π= 1₁⁺ - 4₁⁺ multiplet, whose energies must be determined to study the influence of the proximity of the continuum on the corresponding proton-neutron interaction. The J^π = 1₁⁺, 2₁⁺, 4₁⁺ bound states have been determined, and only a clear identification of the J^π = 3₁⁺ is missing. Purpose: We wish to complete the study of the J^π = 1₁⁺ - 4₁⁺multiplet in ²⁶F, by studying the energy and width of the J^π = 3₁⁺unbound state. The method was first validated by the study of unbound states in ²⁵, for which resonances were already observed in a previous experiment. Method: Radioactive beams of ²⁶Ne and ²⁷Ne, produced at about 440AMeV by the fragment separator at the GSI facility were used to populate unbound states in ²⁵F and ²⁶F via one-proton knockout reactions on a CH₂ target, located at the object focal point of the R³B/LAND setup. The detection of emitted. γ and neutrons, added to the reconstruction of the momentum vector of the A - 1 nuclei, allowed the determination of the energy of three unbound states in ²⁵F and two in ²⁶F. Results: Based on its width and decay properties, the first unbound state in ²⁵F, at the relative energy of 49(9) keV, is proposed to be a J^π = 1/ 2ˉ arising from a p_(1/2) proton- hole state. In ²⁶F, the first resonance at 323(33) keV is proposed to be the J^π = 3₁⁺ member of the J^π = 1₁⁺- 4₁⁺multiplet. Energies of observed states in ²⁵ʼ²⁶F have been compared to calculations using the independent-particle shell model, a phenomenological shell model, and the ab initio valence-space in-medium similarity renormalization group method. Conclusions: The deduced effective proton- neutron interaction is weakened by about 30-40% in comparison to the models, pointing to the need for implementing the role of the continuum in theoretical descriptions or to a wrong determination of the atomic mass of ²⁶F.
publishDate 2019
dc.date.none.fl_str_mv 2019
2019-11-08
2019
2019-11-08
dc.type.none.fl_str_mv journal article
http://purl.org/coar/resource_type/c_6501
dc.type.openaire.fl_str_mv info:eu-repo/semantics/article
format article
dc.identifier.none.fl_str_mv https://hdl.handle.net/20.500.14352/5952
url https://hdl.handle.net/20.500.14352/5952
dc.language.none.fl_str_mv Inglés
eng
language_invalid_str_mv Inglés
language eng
dc.rights.none.fl_str_mv open access
http://purl.org/coar/access_right/c_abf2
dc.rights.openaire.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv open access
http://purl.org/coar/access_right/c_abf2
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv American Physical Society
publisher.none.fl_str_mv American Physical Society
dc.source.none.fl_str_mv reponame:Docta Complutense
instname:Universidad Complutense de Madrid (UCM)
instname_str Universidad Complutense de Madrid (UCM)
reponame_str Docta Complutense
collection Docta Complutense
repository.name.fl_str_mv
repository.mail.fl_str_mv
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