相关论文: Pionic decay of Lambda Hypernuclei in a Continuum …
A method suitable for extracting resonance parameters of unstable baryons in lattice QCD is examined. The method is applied to the strong decay of the Delta to a pion-nucleon state, extracting the pi-N - Delta coupling constant and Delta…
DWIA calculations of Lambda-hypernuclear production rates in stopped K- reactions on several p-shell targets used recently in experiments by the FINUDA Collaboration are reported. Chirally motivated K- + N -> pion + Lambda in-medium…
The HypHI Collaboration at GSI argued recently for a (Lambda-n-n) bound state from the observation of its two-body (t + pi-) weak-decay mode. We derive constraints from several hypernuclear systems, in particular from the A=4 hypernuclei…
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 study the shape of $\Lambda$ hypernuclei in the full ($\beta,\gamma$) deformation plane, including both axially symmetric and triaxial quadrupole deformations. To this end, we use the constrained Skyrme Hartree-Fock+BCS method on the…
The lifetime of a Lambda particle embedded in a nucleus (hypernucleus) decreases from that of free Lambda decay due to the opening of the Lambda N to NN weak decay channel. However, it is generally believed that the lifetime of a…
Recent theoretical investigations of the decay mechanism out of a superdeformed nuclear band have yielded qualitatively different results, depending on the relative values of the relevant decay widths. We present a simple two-level model…
The $\Lambda$ and neutron decay widths of $\Xi$ hypernuclear states, based on calculated $\Xi N \to \lala$ mixing amplitudes, are estimated. The widths which result from using the Nijmegen Model D interaction are sufficiently small, of…
The nonmesonic weak decay of $\Lambda$ hypernuclei is studied in a shell model framework. A complete strangeness-changing weak $\Lambda N \to NN$ transition potential, based on one boson exchange, is constructed by including the exchange of…
We propose to investigate the effects of new physics in the semi-leptonic sequential decay $\Lambda_b \to \Lambda_c (\to \Lambda \pi) \tau{\bar \nu}_{\tau}$. Firstly, we write the general, model independent, non-covariant expression of the…
Evidence for Nucleon Decay has yet to be observed. Current results from the observation of a 45 kton-year exposure of Super-Kamiokande and lifetime limits for nucleons to decay via lepton + pion, lepton + eta and lepton + kaon modes are…
The nonmesonic weak decay of $\Lambda$ hypernuclei using nonrelativistic nuclear matter is studied. As the basic building block we use the Polarization Propagator Method developed by Oset and Salcedo. It is shown that the exact calculation…
The most general amplitude for the radiative pion decay pi -> e nu gamma including terms beyond V-A theory is considered. The experimental constraints on the decay amplitude components are discussed. A model independent presentation of the…
The weak nonmesonic decay of Lambda-hypernuclei is studied in the context of a one-meson-exchange model. Predictions are made for the decay rate, p/n stimulation ratio and the asymmetry in polarized hypernuclear decay.
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 evaluate the $a_1(1260) \to \pi \sigma (f_0(500))$ decay width from the perspective that the $a_1(1260)$ resonance is dynamically generated from the pseudoscalar-vector interaction and the $\sigma$ arises from the…
Using as a tool the s-wave approximation (sWA), this work demonstrates that the nonmesonic weak decay transition rates $\Gamma_{n}$ and $\Gamma_{p}$ can be expressed in all hypernuclei up to $^{29}_\Lambda $Si (and very likely in heavier…
We investigate the A$(\pi^+,K^+){_\Lambda}$A reaction within a covariant model. We consider those amplitudes which are described by creation, propagation and decay into relevant channel of $N^*$(1650), $N^*$(1710), and $N^*$(1720)…
Leptonic decay widths and leptonic decay constants of light vector mesons and weak leptonic decay widths and weak decay constants of light and heavy pseudoscalar mesons have been studied in a field- theoretic framework based on the…
The $\Delta$ decay in the nuclear medium is calculated in the relativistic meson-nucleon model. The delta spreading width is calculated and compared with the Pauli-blocked $\pi$N decay width. The influence of relativistic mean fields is…