Hypernuclear Weak Decay Puzzle
| dc.creator | Barbero, C. | |
| dc.creator | Horvat, D. | |
| dc.creator | Krmpotic, F. | |
| dc.creator | Kuo, T. T. S. | |
| dc.creator | Naranvcic, Z. | |
| dc.creator | Tadić, D. | |
| dc.date | 2000-11-28 | |
| dc.date | 2002-09-20 | |
| dc.date.accessioned | 2026-07-07T05:38:22Z | |
| dc.date.available | 2026-07-07T05:38:22Z | |
| dc.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 Pauli Principle, and a very simple expression is derived for the neutron and proton induced decays rates, $Γ_n$ and $Γ_p$, which does not involve the spectroscopic factors. We use the standard strangeness-changing weak $ΛN\to NN$ 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 ${^{12}_ΛC}$ is carefully analyzed. With the commonly used parametrization in the One-Meson-Exchange Model (OMEM), the calculated rate $Γ_{NM}= Γ_n+Γ_p$ is of the order of the free $Λ$ decay rate $Γ^0(Γ_{NM}^{\rm th}\cong Γ^0)$ and is consistent with experiments. Yet, the measurements of $Γ_{n/p}=Γ_n/Γ_p$ and of $Γ_p$ are not well accounted for by the theory ($Γ_{n/p}^{\rm th}\lsim 0.42; Γ_p^{\rm th}\gsim 0.60 Γ^0$). It is suggested that, unless additional degrees of freedom are incorporated, the OMEM parameters should be radically modified. | |
| dc.description | 44 pages, 2 eps figures, revtex, to appear in Phys. Rev. C | |
| dc.identifier | https://arxiv.org/abs/nucl-th/0011092 | |
| dc.identifier | http://arxiv.org/abs/nucl-th/0011092 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/81592 | |
| dc.subject | Nuclear Theory | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | Hypernuclear Weak Decay Puzzle | |
| dc.type | text |