Related papers: Weak Radiative Hyperon Decays: Questioning the Bas…
We consider the predictions of chiral perturbation theory for $SU(3)$ breaking in weak semileptonic and $s$-wave nonleptonic hyperon decays. By defining an expansion sensitive only to $SU(3)$ breaking, we show that the leading corrections…
A dark photon is a well-motivated new particle which, as a component of an associated dark sector, could explain dark matter. One strong limit on dark photons arises from excessive cooling of supernovae. We point out that even at couplings…
The non-mesonic weak decay of $\Lambda$-hypernuclei is studied within a microscopic diagrammatic approach which includes, for the first time, the effect or the $\Delta$-baryon resonance. We adopt a nuclear matter formalism extended to…
We propose the use of B -->D^**K decay modes for a theoretically clean determination of the weak phase gamma. The self tagging decays of the neutral D^** mesons, makes a measurement of the b --> u\bar{c}s amplitude feasible. This overcomes…
In this work, we perform a analysis of semi-leptonic and nonleptonic weak decays of heavy baryons: $\Lambda_{b},\Xi_{b},\Omega_{b}$ and $\Lambda_{c},\Xi_{c},\Omega_{c}$. For nonleptonic decay modes, we study only the factorizable channels…
Baryons with three heavy quarks are the last missing pieces of the lowest-lying baryon multiplets in the quark model after the discovery of doubly heavy baryons. In this work, we study nonleptonic weak decays of triply heavy baryons…
The implications of chiral $SU(3)_L \times SU(3)_R$ symmetry and heavy quark symmetry for the radiative decays $D^{*0}\to D^0\gamma$, $D^{*+}\to D^+\gamma$, and $D_s^*\to D_s\gamma$ are discussed. Particular attention is paid to $SU(3)$…
Within the collective coordinate approach to chiral soliton models we suggest that breaking of SU(3) flavor symmetry mainly resides in the baryon wave-functions while the charge operators have no (or only small) symmetry breaking…
The most important hint of physics beyond the Standard Model (SM) from the 1995 precision electroweak data is that the most precisely measured quantities, the total, leptonic and hadronic decay widths of the $Z$ and the effective weak…
We analyze the degree to which parity-violating (PV) electroexcitation of the $\Delta(1232)$ resonance may be used to extract the weak neutral axial vector transition form factors. We find that the axial vector electroweak radiative…
We re-examine the puzzling $\pi^+$ emission from the weak decay of $^4_\Lambda$He and propose an explanation in terms of a three-body decay of the virtual $\Sigma^+$. Such a resolution of the $\pi^+$ decay puzzle is consistent with the…
Motivated by the very important discovery of CP violation in charm-decays for the first time, by the LHCb collaboration, the role of nearby resonances such as the scalar $f_0(1710)$ in accounting for the observed CP is discussed. It is…
We calculate the leading contribution to the weak $\Lambda \Lambda K$ coupling in heavy baryon chiral perturbation theory, including the SU(3) breaking terms arising at one-loop. This coupling gives the leading one-boson exchange amplitude…
We first review the methods for determining gamma from B->D K decays that appeared after CKM 2008. We then discuss the theoretical errors in gamma extraction. The errors due to neglected D-Dbar and B_{d,s}-Bbar_{d,s} mixing can be avoided…
Weak gravitational lensing observations probe the spectrum and evolution of density fluctuations and the cosmological parameters which govern them but are currently limited to small fields and subject to selection biases. We show how the…
We find that the $CP$-violating asymmetry $$ \frac{\Gamma \left(t \rightarrow bW^+ \right) - \Gamma \left(\bar{t} \rightarrow \bar{b}W^- \right)} {\Gamma \left(t \rightarrow bW^+ \right) + \Gamma \left(\bar{t} \rightarrow \bar{b}W^-…
Dark matter particles need not be completely stable, and in fact they may be decaying now. We consider this possibility in the frameworks of universal extra dimensions and supersymmetry with very late decays of WIMPs to Kaluza-Klein…
We report on a study of the sequential hyperon decay $\Sigma^0\rightarrow\Lambda \gamma;\Lambda\rightarrow p\pi^- $ and its corresponding anti-hyperon decay. We derive a multi-dimentional and model-independent formalism for the case when…
A general parametrization of the amplitudes for the rare two-body decays B -> pi K is introduced, which makes maximal use of theoretical constraints arising from flavour symmetries of the strong interactions and the structure of the…
We study the |Delta I|=3/2 amplitudes of hyperon non-leptonic decays of the form B->B'+pi in the context of chiral perturbation theory. The lowest-order predictions are determined in terms of only one unknown parameter and are consistent…