Related papers: The Non-Mesonic Weak Decay of Double-Lambda Hypern…
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…
The $\lambda$ mechanism ($W_L$-$W_R$ exchange) of the neutrinoless double beta decay ($0\nu\beta\beta$-decay), which has origin in left-right symmetric model with right-handed gauge boson at TeV scale, is investigated. The revisited…
I review the current status of understanding the mechanism of the nonmesonic weak decays (NMWD) of hypernuclei. Long standing problem on the Gamma_n/Gamma_p ratio has been solved by considering short-range weak interactions properly. This…
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…
The physics of the weak decay of hypernuclei is briefly reviewed from a theoretical point of view. Special regard is devoted to the recent progress concerning the determination of the non--mesonic decay widths and the asymmetry parameters.…
We analyze the recent data on the non-mesonic decays of light Lambda-hypernuclei up to ^12_Lambda C using the phenomenological model of Block and Dalitz. Fitting the spin-isospin dependent Lambda N -> NN reaction rates to six data points,…
The ratio N_{nn}/N_{np} between the number of neutron-neutron and neutron--proton pairs emitted in the non--mesonic weak decay of \Lambda-hypernuclei is calculated within a nuclear matter formalism extended to ^{12}_{Lambda}C via the local…
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…
New spectra from the FINUDA experiment of the Non Mesonic Weak Decay (NMWD) proton kinetic energy for 9(Lambda)Be, 11(Lambda)B, 12(Lambda)C, 13(Lambda)C, 15 (Lambda)N and 16(Lambda)O are presented and discussed along with the published data…
We present a nonrelativistic transition potential for the weak strangeness-changing reaction $\Lambda N \to NN$. The potential is based on a one meson exchange model (OME), where, in addition to the long-ranged pion, the exchange of the…
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…
The nonmesonic weak decay spectra of light hypernuclei have been evaluated in a systematic way. As theoretical framework we adopt the independent particle shell model with three different one-meson-exchange transition potentials. Good…
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…
In this contribution we discuss an evaluation of double-nucleon coincidence spectra for the non-mesonic weak decay of Lambda-hypernuclei. The results have been obtained by combining a one-meson-exchange model for the Lambda N -> nN…
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…
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,…
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…
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…
A direct experimental evidence of the occurrence of the weak reaction $\Lambda np\rightarrow nnp$ in nuclei has been obtained by the FINUDA experiment. Three events have been found that can be attributed to $^{7}_{\Lambda}$Li and…
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…