Kinematical and nonlocality effects on the nonmesonic weak hypernuclear decay

Abstract

We derive in detail the transition potential for nonmesonic lambda-hypernuclear decay in a one-meson-exchange model involving the full pseudoscalar and vector meson octets and including two effects that have been systematically omitted in the literature. These are the kinematical effects due to the difference between the lambda and nucleon masses and the first-order nonlocality corrections. Numerical results for ${}_{\Lambda }^{12}$C and ${}_{\Lambda }^5$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, the neutron-to-proton branching ratio, and the asymmetry parameter. The latter two still cannot be reconciled with the available experimental data. The existing theoretical predictions for the sign of the asymmetry parameter in ${}_{\Lambda }^5$He are confirmed.

36 pages; LaTeX2e; 1 eps figure. Changes: 2 more tables and 14 new references added; effects on asymmetry parameter calculated; discussions expanded; more definite conclusions reached

References in corpus (17)

• The Weak Decay of Hypernuclei
• Weak Decay of Lambda Hypernuclei
• Theory of Weak Hypernuclear Decay
• Meson exchange in the weak decay of Lambda hypernuclei and the Gamma_n/Gamma_p ratio
• Final State Interactions in Hypernuclear Decay
• Neutron and proton spectra from the decay of $\Lambda$ hypernuclei
• Weak Decay of $\Lambda$ in Nuclei : Quarks vs Mesons
• Weak Decay of Lambda Hypernuclei
• Non-mesonic Weak Decays of Light Hypernuclei in the Direct Quark and the One-Pion Exchange Mechanisms
• Direct quark transition potential for $\Lambda N\to NN$ decay
• Weak decays of medium and heavy Lambda-hypernuclei
• Erratum: Neutron and proton spectra from the decay of $\Lambda$ hypernuclei [Phys. Rev. C55, 735 (1997)]
• Nonmesonic Weak Decay of $\Lambda$ Hypernuclei within a Nuclear Matter Formalism
• Spin observables in the $pn\to p\Lambda$ reaction
• Role of deformation in the nonmesonic decay of light hypernuclei
• Relativistic Treatment of Hypernuclear Decay
• Nuclear Structure in Nonmesonic Weak Decay of Hypernuclei

Cited by in corpus (14)

• Strangeness in nuclear physics
• Strangeness nuclear physics: a critical review on selected topics
• Single and double coincidence nucleon spectra in the weak decay of Lambda hypernuclei
• Asymmetries in the Non-Mesonic Weak Decay of Polarized Lambda-Hypernuclei
• Asymmetry parameter for nonmesonic hypernuclear decay
• $\sigma$ meson exchange effect on nonmesonic hypernuclear weak decay observables
• Kinetic energy sum spectra in nonmesonic weak decay of hypernuclei
• s-Wave Approximation for Asymmetry in Nonmesonic Decay of Finite Hypernuclei
• Relationships between nonmesonic-weak-decays in different hypernuclei
• Nonmesonic weak decay spectra of ${}_{\Lambda }^4$He
• Nonmesonic weak decay spectra of light hypernuclei
• Nonmesonic weak decay of charmed hypernuclei
• Nonmesonic Weak Decay Dynamics from proton spectra of $\Lambda$-Hypernuclei
• Relativistic model for the nonmesonic weak decay of single-lambda hypernuclei