Related papers: Weak Decay of Lambda Hypernuclei
After a short introduction to the nonmesonic weak decay (NMWD) $\Lambda N\go nN$ of $\Lambda$-hypernuclei we discuss the long-standing puzzle on the ratio $\Gamma_n/\Gamma_p$, and some recent experimental evidences that signalized towards…
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…
We analyze the influence of $\sigma$ meson exchange on the main nonmesonic hypernuclear weak decay observables: the total rate, $\Gamma_{NM}$, the neutron-to-proton branching ratio, $\Gamma_{n/p}$, and the proton asymmetry parameter,…
We have measured both yields of neutron-proton and neutron-neutron pairs emitted from the non-mesonic weak decay process of 5_Lambda-He and 12_Lambda-C hypernuclei produced via the (pi^+,K^+) reaction for the first time. We observed clean…
We develop a theoretical framework for the evaluation of the coincidence number of pairs, $N_{nN}$, and the asymmetry parameter, $a_\Lambda$, in nonmesonic hypernuclear decay $\Lambda N\rightarrow nN$. The primary nomesonic weak…
We present an evaluation of the non-mesonic decay widths for Lambda-hypernuclei (Lambda N --> NN, Lambda NN --> NNN) within the framework of the polarization propagator method. The full Lambda self-energy is evaluated microscopically in…
We take an approach to the $\Lambda$ nonmesonic weak decay in nuclei based on the exchange of mesons under the guidelines of chiral Lagrangians. The one pion and one kaon exchange are considered, together with the exchange of two pions,…
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 $\Lambda$…
Using the recent measurement of the $\Xi ^0 \to \Lambda \gamma $ asymmetry as an input, we reanalyse nonleptonic and weak radiative hyperon decays in a single symmetry-based framework. In this framework the old S:P problem of nonleptonic…
It is shown that the mass dependence of the $\Lambda$-lifetime in heavy hypernuclei is sensitive to the ratio of neutron-induced to proton-induced non-mesonic decay rates R_n/R_p. A comparison of the experimental mass dependence of the…
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…
Based on realistic calculations for the nonmesonic decay rate of Hypertriton we demonstrate, that in principle it is not possible to measure the total n- and p- induced decay rates and as a consequence $\Gamma_n /\Gamma_p$ for that lightest…
$\Lambda^+_c$ hypernuclei are expected to have binding energies and other properties similar to those of strange hypernuclei in view of the similarity between the quark structures of the strange and charmed hyperons, namely $\Lambda(uds)$…
The nonmesonic weak decay width of $^{12}_{\Lambda}C$ hypernucleus has been evaluated within a nuclear matter formalism, using the local density approximation. In addition to the one-body induced decay $(\Lambda N \to n N)$, it has been…
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 ${\mathrm{^{12}_{\Lambda}C}}$…
Main theoretical approaches to weak radiative hyperon decays are briefly reviewed. It is emphasized that only approaches with great predictive power should be seriously considered when seeking a resolution of the puzzle presented by…
The Non-Mesonic (NM) decay of $^4_\Lambda{\mathrm{He}}$ and $^5_\Lambda{\mathrm{He}}$ in two-body channels has been studied by the FINUDA Collaboration. Two-body NM decays of hypernuclei are rare and the existing observations and…
The lifetime of the Lambda hyperon in heavy hypernuclei as measured by the COSY-13 Collaboration in proton - Au, Bi and U collisions has been analysed to yield tau(Lambda) = (145 +- 11) ps. This value for tau(Lambda) is compatible with the…
Hypernuclei are convenient laboratory to study the baryon-baryon weak interaction and associated effective Hamiltonian. The strangeness changing process, in which a Lambda hyperon converts to a neutron with a release up to 176 MeV, provides…
The $\Lambda$-$\Lambda$ effective interaction, in the channel $L=S=0$, in the nuclear medium is fitted to the available binding energies, $B_{\Lambda\Lambda}$, of double $\Lambda$ hypernuclei: $^{6}_{\Lambda\Lambda}$He,…