Hypernuclear weak decay puzzle
A general shell model formalism for the nonmesonic weak decay of the hypernuclei has been developed. It involves a partial wave expansion of the emitted nucleon waves, preserves naturally the antisymmetrization between the escaping particles and the residual core, and contains as a particular case t...
| Autores principales: | , , , , , |
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| Formato: | Articulo |
| Lenguaje: | Inglés |
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2002
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| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/125943 |
| Aporte de: |
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I19-R120-10915-125943 |
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dspace |
| institution |
Universidad Nacional de La Plata |
| institution_str |
I-19 |
| repository_str |
R-120 |
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SEDICI (UNLP) |
| language |
Inglés |
| topic |
Ciencias Exactas Física general shell model formalism nonmesonic weak decay hypernuclei |
| spellingShingle |
Ciencias Exactas Física general shell model formalism nonmesonic weak decay hypernuclei Barbero, César Alberto Horvat, Dubravko Krmpotić, Francisco Kuo, T. T. S. Narančić, Zoran Tadić, Dubravko Hypernuclear weak decay puzzle |
| topic_facet |
Ciencias Exactas Física general shell model formalism nonmesonic weak decay hypernuclei |
| description |
A general shell model formalism for the nonmesonic weak decay of the hypernuclei has been developed. It involves a partial wave expansion of the emitted nucleon waves, preserves naturally the antisymmetrization between the escaping particles and the residual core, and contains as a particular case the weak Λ-core coupling formalism. The extreme particle-hole model and the quasiparticle Tamm-Dancoff approximation are explicitly worked out. It is shown that the nuclear structure manifests itself basically through the Pauli principle, and a very simple expression is derived for the neutron- and proton-induced decays rates Γ<sub>n</sub> and Γ<sub>p</sub>, which does not involve the spectroscopic factors. We use the standard strangeness-changing weak ΛN→NN transition potential which comprises the exchange of the complete pseudoscalar and vector meson octets (π,η,K,ρ,ω,K*), taking into account some important parity-violating transition operators that are systematically omitted in the literature. The interplay between different mesons in the decay of ¹²<sub>Λ</sub>C is carefully analyzed. With the commonly used parametrization in the one-meson-exchange model (OMEM), the calculated rate Γ<sub>NM</sub> = Γ<sub>n</sub> + Γ<sub>p</sub> is of the order of the free Λ decay rate Γ⁰(Γ<sup>th</sup><sub>NM</sub> ≅ Γ⁰) and is consistent with experiments. Yet the measurements of Γ<sub>n/p</sub> = Γ<sub>n</sub> / Γ<sub>p</sub> and of Γ<sub>p</sub> are not well accounted for by the theory (Γ<sup>th</sup><sub>n/p</sub> ≲ 0.42,Γ<sup>th</sup><sub>p</sub> ≳ 0.60Γ⁰). It is suggested that, unless additional degrees of freedom are incorporated, the OMEM parameters should be radically modified. |
| format |
Articulo Articulo |
| author |
Barbero, César Alberto Horvat, Dubravko Krmpotić, Francisco Kuo, T. T. S. Narančić, Zoran Tadić, Dubravko |
| author_facet |
Barbero, César Alberto Horvat, Dubravko Krmpotić, Francisco Kuo, T. T. S. Narančić, Zoran Tadić, Dubravko |
| author_sort |
Barbero, César Alberto |
| title |
Hypernuclear weak decay puzzle |
| title_short |
Hypernuclear weak decay puzzle |
| title_full |
Hypernuclear weak decay puzzle |
| title_fullStr |
Hypernuclear weak decay puzzle |
| title_full_unstemmed |
Hypernuclear weak decay puzzle |
| title_sort |
hypernuclear weak decay puzzle |
| publishDate |
2002 |
| url |
http://sedici.unlp.edu.ar/handle/10915/125943 |
| work_keys_str_mv |
AT barberocesaralberto hypernuclearweakdecaypuzzle AT horvatdubravko hypernuclearweakdecaypuzzle AT krmpoticfrancisco hypernuclearweakdecaypuzzle AT kuotts hypernuclearweakdecaypuzzle AT naranciczoran hypernuclearweakdecaypuzzle AT tadicdubravko hypernuclearweakdecaypuzzle |
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Repositorios |
| _version_ |
1764820452512890883 |