Related papers: Weak decays of 4He-Lambda
We first determine the Lambda-N S-wave phase shifts so as to reproduce the experimental Lambda separation energies of A=3, 4 Lambda-hypernuclei, and then construct three phase-equivalent Lambda-N potentials with different central repulsion.…
A neutron decays into a proton, an electron, and an anti-neutrino through the beta-decay process. The decay lifetime ($\sim$880 s) is an important parameter in the weak interaction. For example, the neutron lifetime is a parameter used to…
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…
A precise measurement of the hypertriton lifetime is presented. In this letter, the mesonic decay modes $\mathrm{{^3_\Lambda}H \rightarrow ^3He + \pi^-}$ and $\mathrm{{^3_\Lambda}H \rightarrow d + p + \pi^-}$ are used to reconstruct the…
The self-consistent proton-neutron quasiparticle random phase approximation approach is employed to calculate $\beta$-decay half-lives of neutron-rich even-even nuclei with $8\leqslant Z \leqslant 30$. A newly proposed nonlinear…
We have searched for proton decays into a charged antilepton ($e^+$, $\mu^+$) plus a meson ($\eta$, $\rho^0$, $\omega$) and neutron decays into a charged antilepton ($e^+$, $\mu^+$) plus a meson ($\pi^-$, $\rho^-$) using Super-Kamiokande…
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…
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…
Nonmesonic decays of $\Lambda$ in nuclear medium and light hypernuclei are studied by using the $\Lambda N \to NN$ weak transition potential derived from the meson exchange mechanism and the direct quark mechanism. The long range part of…
We study the nonmesonic weak decay (NMWD) $\Lambda N \to nN$ of the ${}^{12}_{\Lambda} C$ hypernucleus induced by the nucleon $N=n,p$ with transition rate $\Gamma_N$. The nuclear process is described by the interplay of two models; one…
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…
Accurate measurement of the lifetime of the neutron (which is unstable to beta decay) is important for understanding the weak nuclear force and the creation of matter during the Big Bang. Previous measurements of the neutron lifetime have…
At the Mainz Microtron MAMI, the first high-resolution pion spectroscopy from decays of strange systems was performed by electron scattering off a Be-9 target in order to study the ground-state masses of Lambda-hypernuclei. Positively…
The main open problem in the physics of Lambda-hypernuclei is the lack of a sound theoretical interpretation of the large experimental values for the ratio G_n/G_p. To approach the problem, we have incorporated a Lambda N-> nN…
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 $\Lambda N\rightarrow NN$,…
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…
Searches for a nucleon decay into a charged anti-lepton (e^+ or {\mu}^+) plus a light meson ({\pi}^0, {\pi}^-, {\eta}, {\rho}^0, {\rho}^-, {\omega}) were performed using the Super-Kamiokande I and II data. Twelve nucleon decay modes were…
Evidence for the neutron-rich hypernucleus 6{\Lambda}H is presented from the FINUDA experiment at DA{\Phi}NE, Frascati, studying ({\pi}+, {\pi}-) pairs in coincidence from the K- +6Li \rightarrow 6 H+{\pi}+ production reaction followed by…
We calculate the lifetime of the hypertriton as function of the $\Lambda$ separation energy $B_\Lambda$ in an effective field theory with $\Lambda$ and deuteron degrees of freedom. We also consider the impact of new measurements of the weak…
The most precise measurements to date of the $^{3}_{\Lambda}\mathrm H$ lifetime $\tau$ and $\Lambda$ separation energy ${\rm B}_{\Lambda}$ are obtained using the data sample of Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=$ 5.02 TeV…