Related papers: Nonmesonic weak decay of $\Lambda$ hypernuclei wit…
We have measured the angular correlation of the pair nucleons np and nn emitted from the nonmesonic weak decay (NMWD) of ^{12}_{Lambda}C produced via the (pi^+,K^+) reaction in coincidence measurement. The Lambda p -> np and Lambda n -> nn…
We have measured the energy spectra of pions and protons emitted in the weak decay of 12_Lambda_C, 28_Lambda_Si, and Lambda_Fe hypernuclei produced via the (pi+, K+) reaction. The decay widths of the pi- mesonic decay (Lambda -> p + pi-)…
Previous studies of proton and neutron spectra from Non-Mesonic Weak Decay of eight Lambda-Hypernuclei (A = 5-16) have been revisited. New values of the ratio of the two-nucleon and the one-proton induced decay widths, Gamma_2N/Gamma_p, are…
The Lambda decay rates in nuclei has been calculated in ref. 1 using the Propagator Method in Local Density Approximation. We have studied the dependence of the widths (including the one for the two-body induced process Lambda NN -> NNN) on…
Because of Pauli suppression effects the $N\pi$ decay of the free $\Lambda$ is not of importance in hypernuclei with $A\geq 10$. Rather the decay of such hypernuclei proceeds via the nucleon-stimulated mode $\Lambda N\rightarrow NN$,…
We compute for the first time the decay width of lambda-hypernuclei in a relativistic mean-field approximation to the Walecka model. Due to the small mass difference between the lambda-hyperon and its decay products---a nucleon and a…
We performed a coincidence measurement of two nucleons emitted from the nonmesonic weak decay (NMWD) of ^{5}_{\Lambda}He formed via the ^{6}Li(\pi^+,K^+) reaction. The energies of two nucleons and the pair number distributions in the…
We review the mechanism of weak decay of hypernuclei, with emphasis on the non-mesonic decay channels. Various theoretical approaches are discussed and the results are compared with the available experimental data.
Nonmesonic weak decays of s-shell hypernuclei are analyzed in microscopic models for the Lambda N to NN weak interaction. A scalar-isoscalar meson, sigma, is introduced and its importance in accounting the decay rates, n/p ratios and proton…
We study the non-mesonic weak decay of the doubly-strange hypernucleus $^{\Lambda\Lambda}_6$He within a model which considers the exchange of pseudoscalar and vector mesons. Special attention is paid into quantifying the strong interaction…
The nonleptonic weak $|\Delta S|=1$ $\Lambda N$ interaction, responsible for the dominant, nonmesonic decay of all but the lightest hypernuclei, is studied in the framework of an effective field theory. The long-range physics is described…
Contributions of the direct quark mechanism are studied in the nonmesonic weak decays of light hypernuclei. The $\Lambda N \to NN$ transition is described by the one pion exchange mechanism and the direct quark mechanism, induced by the…
One of the main open problems in the physics of Lambda-hypernuclei is the lack of a sound theoretical interpretation of the large experimental values for the ratio Gn/Gp=G(Lambda n -> nn)/G(Lambda p -> np). To approach the problem, we have…
Non-mesonic decay of kaonic nuclei is investigated under a Lambda(1405) doorway picture where the Kbar absorptions in nuclei take place through the Lambda(1405) resonance. Calculating Lambda(1405) N to YN transitions in one-meson exchange,…
We have evaluated the nonmesonic weak decay spectra within the independent-particle shell-model, and compared them with the recent measurements of: i) the single and double coincidence nucleon spectra in ${\mathrm{^{12}_{\Lambda}C}}$…
The strangeness-changing ($\Delta S = 1$) weak baryon-baryon interaction is studied through the nonmesonic weak decay of double-$\Lambda$ hypernuclei. Besides the usual nucleon-induced decay $\Lambda N \to N N$ we discuss novel…
To comprehend the recent Brookhaven National Laboratory experiment E788 on $^4_\Lambda$He, we have outlined a simple theoretical framework, based on the independent-particle shell model, for the one-nucleon-induced nonmesonic weak decay…
Two different approaches have been employed for the evaluation of the decay widths of Lambda-hypernuclei (ranging from $^5_{\Lambda}$He to $^{208}_{\Lambda}$Pb) with the polarization propagator method. In ref.[1], the two-nucleon stimulated…
We discuss the nonmesonic decay of deformed p-shell hypernuclei. The Nilsson model with angular momentum projection is employed in order to take into account the deformation effects. The nonmesonic decay rate and the intrinsic $\Lambda$…
We derive general explicit expressions for a shell-model calculation of the intrinsic asymmetry parameter, $a_\Lambda$, in nonmesonic weak hypernuclear decay. They include the effects of three-body kinematics in the final states of the…