Meson exchange in the weak decay of Lambda hypernuclei and the Gamma_n/Gamma_p ratio

Abstract

We take an approach to the Lambda non-mesonic weak decay in nuclei based on the exchange of mesons. The one pion and one kaon exchange are considered, together with the exchange of two pions, either correlated, leading to an important scalar-isoscalar exchange (sigma-like exchange), or uncorrelated (box diagrams). Extra effects of omega exchange in the scalar-isoscalar channel are also considered. Constraints of chiral dynamics are used to generate these exchanges. A drastic reduction of the OPE results for the Gamma_n/Gamma_p ratio is obtained and the new results are compatible with all present experiments within errors. The absolute rates obtained for different nuclei are also in good agreement with experiment.

30 pages, 16 figures, 8 tables, to be published in Nucl. Phys. A

Cited by in corpus (35)

• Strangeness in nuclear physics
• Weak Decay of Lambda Hypernuclei
• Strangeness nuclear physics: a critical review on selected topics
• Final State Interactions in Hypernuclear Decay
• Towards the solution of the Gn/Gp Puzzle in the Non-Mesonic Weak Decay of Lambda-Hypernuclei
• Coincidence Measurement of the Nonmesonic Weak Decay of ^{12}_{Lambda}C
• Nucleon-Nucleon Coincidence Spectra in the Non-Mesonic Weak Decay of Lambda-Hypernuclei and the n/p Puzzle
• Properties of the rho and sigma Mesons from Unitary Chiral Dynamics
• Nonmesonic weak decay of light hypernuclei with coherent $\Sigma$ mixing
• Lambda(1405)-induced non-mesonic decay in kaonic nuclei
• Sigma Exchange in the Nonmesonic Decays of Light Hypernuclei and Violation of the Delta I=1/2 Rule
• Branching ratios of mesonic and nonmesonic antikaon absorptions in nuclear medium
• Exchange terms in the two--nucleon induced non--mesonic weak decay of $\Lambda$--hypernuclei
• $\Lambda N\to NN$ weak interaction in effective field theory
• Two-pion-exchange in the non-mesonic weak decay of $\Lambda$-hypernuclei
• Single and double coincidence nucleon spectra in the weak decay of Lambda hypernuclei
• Kinematical and nonlocality effects on the nonmesonic weak hypernuclear decay
• Asymmetries in the Non-Mesonic Weak Decay of Polarized Lambda-Hypernuclei
• Scalar Lambda N and Lambda Lambda interaction in a chiral unitary approach
• The phi NN coupling from chiral loops
• Nonmesonic Weak Decay of $\Lambda$ Hypernuclei within a Nuclear Matter Formalism
• Novel Weak Decays in Doubly Strange Systems
• $\sigma$ meson exchange effect on nonmesonic hypernuclear weak decay observables
• Quantum interference terms in nonmesonic weak decay of $\Lambda$-hypernuclei within a RPA formalism
• The $\sigma K$ coupling in the chiral unitary approach and the isoscalar $\bar{K}N$, $\bar{K}A$ interaction
• An EFT for the weak $\Lambda N$ interaction
• Nonmesonic weak decay of $\Lambda$ hypernuclei within a nuclear matter framework
• One-loop contributions in the EFT for the $\Lambda N\to NN$ transition
• s-Wave Approximation for Asymmetry in Nonmesonic Decay of Finite Hypernuclei
• Two pion mediated scalar isoscalar NN interaction in the nuclear medium
• The $\Lambda \Lambda \to YN$ Weak Transition in Double-$\Lambda$ Hypernuclei
• Microscopic approach to the proton asymmetry in the non-mesonic weak decay of Lambda-hypernuclei
• Non-Mesonic Weak Decay of Lambda-hypernuclei: a new determination of the Gn/Gp ratio
• The $\rho NN$ coupling with direct coupling and loops
• Lambda(1405) N to Y N transition in nuclear medium for non-mesonic absorption of Kbar in nucleus