Related papers: Weak radiative hyperon decays
By describing strong interactions between hadrons via a relativistic supermultiplet scheme and regarding weak interactions as a perturbation thereof, we derive expressions for nonleptonic weak decay amplitudes in terms of constituent quark…
We calculate the decay width of the $\Lambda_{c}^{+}\to\Sigma^{+}\gamma$ using light-cone sum rules. For the initial quark radiation an effective Hamiltonian is constructed, where the internal quark line shrinks to a point. The final quark…
Among the light baryons, the $J^\pi = \frac{1}{2}^-$ $\Lambda(1405)$ hyperon is an important special case as it sits just below the $N\bar{K}$ threshold and decays almost exclusively to $\Sigma\pi$. Some long-standing hypotheses for…
The non-leptonic two-body weak decays $\Sigma^{+} \to p \pi^{0}$ and $\bar{\Sigma}^{-} \to \bar{p} \pi^{0}$ are investigated, utilizing $(1.0087\pm0.0044)\times10^{10}$ $J/\psi$ events and $(2.7124\pm0.0143)\times10^{9}$ $\psi(3686)$ events…
The weak radiative decay of $D^0\to V\gamma$ with $V=\bar{K}^0$, and $\phi$, $\rho^0$, and $\omega$, is systematically studied in the vector meson dominance (VMD) model. It allows us to distinguish the short-distance mechanisms which can be…
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…
The non--mesonic weak decay of double--$\Lambda$ hypernuclei is studied within a microscopic diagrammatic approach. Besides the nucleon--induced mechanism, $\Lambda N\to nN$, widely studied in single--$\Lambda$ hypernuclei, additional…
Cabibbo-allowed two-body hadronic weak decays of bottom baryons are analyzed. Contrary to the charmed baryon sector, many channels of bottom baryon decays proceed only through the external or internal W-emission diagrams. Moreover,…
QED gauge invariance, when combined with analyticity, leads to constraints on the low energy end of the emitted photon spectra. This is known as Low's theorem. It is shown that the Ore-Powell result, as well as further developments for the…
An intense X wave propagating perpendicularly to dc magnetic field is unstable with respect to a parametric decay into an electron Bernstein wave and a lower-hybrid wave. A modified theory of this effect is proposed that extends to the…
Weak decays of heavy flavor hadrons play a special role in our understanding of physics of the Standard Model and beyond. The measured quantities, however, result from a complicated interplay of weak and strong interactions. Weak leptonic…
The amplitudes of $K \rightarrow \pi \gamma^* \rightarrow \pi e^+e^-$ and $K \rightarrow \pi \pi \gamma$ decays have been calculated within chiral Lagrangian approach including higher-order derivative terms and meson loops. The…
The nonleptonic decay $\Xi^0_c \to \Lambda^+_c \pi^-$ with $\Delta C=0$ is systematically studied in the framework of the covariant confined quark model with accounting for both short and long distance effects. The short distance effects…
QCD radiative correction to Higgs $\rightarrow$ two photons decay rate is calculated. Below the threshold we found negligible correction, thus supporting results obtained earlier by Djouadi et all [7]. Above the threshold radiative…
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 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.
A search for direct CP violation in the non-leptonic decays of hyperons has been performed. In comparing the product of the decay parameters, $\alpha_{\Xi}\alpha_{\Lambda}$, in terms of an asymmetry parameter, $A_{\Xi\Lambda}$, between…
The Bjorken-Johnson-Low theorem applied to the $\gamma^\ast \to \gamma^\ast \pi^0$ process provides us with a rather remarkable asymptotic behaviour for the $\pi^0 \gamma^\ast \gamma^\ast$ vertex. We compare our result with previous QCD-…
We examine the radiative decays of the Lambda (1405) to octet baryons, Lambda + gamma and Sigma + gamma. In the limit of SU(3) symmetry the decay rates for these two modes are related, and we compute the leading correction to the relation…
Theoretical descriptions of the non-mesonic weak decay of Lambda-hypernuclei are unable to reproduce the experimental values of the ratio Gn/Gp=G(Lambda n -> nn)/G(Lambda p -> np). In this contribution we discuss a new approach to this…