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
- Institución
- Universidad Nacional de La Plata
- OAI Identificador
- oai:sedici.unlp.edu.ar:10915/129673
Ver los metadatos del registro completo
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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 http://purl.org/coar/resource_type/c_6501 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 |
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openAccess |
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http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) |
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