Kinematical and nonlocality effects on the nonmesonic weak hypernuclear decay

Autores
Barbero, César Alberto; De Conti, C.; Galeão, A. P.; Krmpotić, Francisco
Año de publicación
2003
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
We make a careful study about the nonrelativistic reduction of one-meson-exchange models for the nonmesonic weak hypernuclear decay. Starting from a widely accepted effective coupling Hamiltonian involving the exchange of the complete pseudoscalar and vector meson octets (π, η, K, ρ, ω, K*), the strangeness-changing weak ΛN → NN transition potential is derived, including two effects that have been systematically omitted in the literature, or, at best, only partly considered. These are the kinematical effects due to the difference between the lambda and nucleon masses, and the first-order nonlocality corrections, i.e., those involving up to first-order differential operators. Our analysis clearly shows that the main kinematical effect on the local contributions is the reduction of the effective pion mass. The kinematical effect on the nonlocal contributions is more complicated, since it activates several new terms that would otherwise remain dormant. Numerical results for ¹²ΛC and ⁵ΛHe are presented and they show that the combined kinematical plus nonlocal corrections have an appreciable influence on the partial decay rates. However, this is somewhat diminished in the main decay observables: the total nonmesonic rate, Γnm, the neutron-to-proton branching ratio, Γn/ Γp, and the asymmetry parameter, aΛ. The latter two still cannot be reconciled with the available experimental data. The existing theoretical predictions for the sign of aΛ in ⁵ΛHe are confirmed.
Facultad de Ciencias Exactas
Materia
Ciencias Exactas
Física
Hypernuclei
Nonmesonic decay
One-meson-exchange model
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/129673

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spelling Kinematical and nonlocality effects on the nonmesonic weak hypernuclear decayBarbero, César AlbertoDe Conti, C.Galeão, A. P.Krmpotić, FranciscoCiencias ExactasFísicaHypernucleiNonmesonic decayOne-meson-exchange modelWe make a careful study about the nonrelativistic reduction of one-meson-exchange models for the nonmesonic weak hypernuclear decay. Starting from a widely accepted effective coupling Hamiltonian involving the exchange of the complete pseudoscalar and vector meson octets (π, η, K, ρ, ω, K*), the strangeness-changing weak ΛN → NN transition potential is derived, including two effects that have been systematically omitted in the literature, or, at best, only partly considered. These are the kinematical effects due to the difference between the lambda and nucleon masses, and the first-order nonlocality corrections, i.e., those involving up to first-order differential operators. Our analysis clearly shows that the main kinematical effect on the local contributions is the reduction of the effective pion mass. The kinematical effect on the nonlocal contributions is more complicated, since it activates several new terms that would otherwise remain dormant. Numerical results for ¹²<sub>Λ</sub>C and ⁵<sub>Λ</sub>He are presented and they show that the combined kinematical plus nonlocal corrections have an appreciable influence on the partial decay rates. However, this is somewhat diminished in the main decay observables: the total nonmesonic rate, Γ<sub>nm</sub>, the neutron-to-proton branching ratio, Γ<sub>n</sub>/ Γ<sub>p</sub>, and the asymmetry parameter, a<sub>Λ</sub>. The latter two still cannot be reconciled with the available experimental data. The existing theoretical predictions for the sign of a<sub>Λ</sub> in ⁵<sub>Λ</sub>He are confirmed.Facultad de Ciencias Exactas2003-10info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf267-302http://sedici.unlp.edu.ar/handle/10915/129673enginfo:eu-repo/semantics/altIdentifier/issn/0375-9474info:eu-repo/semantics/altIdentifier/arxiv/nucl-th/0212017info:eu-repo/semantics/altIdentifier/doi/10.1016/s0375-9474(03)01620-8info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:31:13Zoai:sedici.unlp.edu.ar:10915/129673Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:31:13.949SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Kinematical and nonlocality effects on the nonmesonic weak hypernuclear decay
title Kinematical and nonlocality effects on the nonmesonic weak hypernuclear decay
spellingShingle Kinematical and nonlocality effects on the nonmesonic weak hypernuclear decay
Barbero, César Alberto
Ciencias Exactas
Física
Hypernuclei
Nonmesonic decay
One-meson-exchange model
title_short Kinematical and nonlocality effects on the nonmesonic weak hypernuclear decay
title_full Kinematical and nonlocality effects on the nonmesonic weak hypernuclear decay
title_fullStr Kinematical and nonlocality effects on the nonmesonic weak hypernuclear decay
title_full_unstemmed Kinematical and nonlocality effects on the nonmesonic weak hypernuclear decay
title_sort Kinematical and nonlocality effects on the nonmesonic weak hypernuclear decay
dc.creator.none.fl_str_mv Barbero, César Alberto
De Conti, C.
Galeão, A. P.
Krmpotić, Francisco
author Barbero, César Alberto
author_facet Barbero, César Alberto
De Conti, C.
Galeão, A. P.
Krmpotić, Francisco
author_role author
author2 De Conti, C.
Galeão, A. P.
Krmpotić, Francisco
author2_role author
author
author
dc.subject.none.fl_str_mv Ciencias Exactas
Física
Hypernuclei
Nonmesonic decay
One-meson-exchange model
topic Ciencias Exactas
Física
Hypernuclei
Nonmesonic decay
One-meson-exchange model
dc.description.none.fl_txt_mv We make a careful study about the nonrelativistic reduction of one-meson-exchange models for the nonmesonic weak hypernuclear decay. Starting from a widely accepted effective coupling Hamiltonian involving the exchange of the complete pseudoscalar and vector meson octets (π, η, K, ρ, ω, K*), the strangeness-changing weak ΛN → NN transition potential is derived, including two effects that have been systematically omitted in the literature, or, at best, only partly considered. These are the kinematical effects due to the difference between the lambda and nucleon masses, and the first-order nonlocality corrections, i.e., those involving up to first-order differential operators. Our analysis clearly shows that the main kinematical effect on the local contributions is the reduction of the effective pion mass. The kinematical effect on the nonlocal contributions is more complicated, since it activates several new terms that would otherwise remain dormant. Numerical results for ¹²<sub>Λ</sub>C and ⁵<sub>Λ</sub>He are presented and they show that the combined kinematical plus nonlocal corrections have an appreciable influence on the partial decay rates. However, this is somewhat diminished in the main decay observables: the total nonmesonic rate, Γ<sub>nm</sub>, the neutron-to-proton branching ratio, Γ<sub>n</sub>/ Γ<sub>p</sub>, and the asymmetry parameter, a<sub>Λ</sub>. The latter two still cannot be reconciled with the available experimental data. The existing theoretical predictions for the sign of a<sub>Λ</sub> in ⁵<sub>Λ</sub>He are confirmed.
Facultad de Ciencias Exactas
description We make a careful study about the nonrelativistic reduction of one-meson-exchange models for the nonmesonic weak hypernuclear decay. Starting from a widely accepted effective coupling Hamiltonian involving the exchange of the complete pseudoscalar and vector meson octets (π, η, K, ρ, ω, K*), the strangeness-changing weak ΛN → NN transition potential is derived, including two effects that have been systematically omitted in the literature, or, at best, only partly considered. These are the kinematical effects due to the difference between the lambda and nucleon masses, and the first-order nonlocality corrections, i.e., those involving up to first-order differential operators. Our analysis clearly shows that the main kinematical effect on the local contributions is the reduction of the effective pion mass. The kinematical effect on the nonlocal contributions is more complicated, since it activates several new terms that would otherwise remain dormant. Numerical results for ¹²<sub>Λ</sub>C and ⁵<sub>Λ</sub>He are presented and they show that the combined kinematical plus nonlocal corrections have an appreciable influence on the partial decay rates. However, this is somewhat diminished in the main decay observables: the total nonmesonic rate, Γ<sub>nm</sub>, the neutron-to-proton branching ratio, Γ<sub>n</sub>/ Γ<sub>p</sub>, and the asymmetry parameter, a<sub>Λ</sub>. The latter two still cannot be reconciled with the available experimental data. The existing theoretical predictions for the sign of a<sub>Λ</sub> in ⁵<sub>Λ</sub>He are confirmed.
publishDate 2003
dc.date.none.fl_str_mv 2003-10
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
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info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/129673
url http://sedici.unlp.edu.ar/handle/10915/129673
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/0375-9474
info:eu-repo/semantics/altIdentifier/arxiv/nucl-th/0212017
info:eu-repo/semantics/altIdentifier/doi/10.1016/s0375-9474(03)01620-8
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
dc.format.none.fl_str_mv application/pdf
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