We analyze charm meson semileptonic $D to V l u_l$ and $Dto P l u_l$ and nonleptonic $D to P V$, $D to PP$ and $D to VV$ decays within a model which combines the heavy quark effective Lagrangian and chiral perturbation theory.
We analyze $D to P V$, $D to PP$ and $D to VV$ decays within a model developed to describe the semileptonic decays $D to V l u_l$ and $Dto P l u_l$. This model combines the heavy quark effective Lagrangian and chiral perturbation theory. We determine amplitudes for decays in which the direct weak annihilation of the initial $D$ meson is absent or negligible, and in which the final state interactions are small. This analysis reduces the arbitrariness in the choice of model parameters. The calculated decay widths are in good agreement with the experimental results.
The semileptonic decays and two-body nonleptonic decays of light baryon octet ($T_8$) and decuplet ($T_{10}$) consisting of light $u,d,s$ quarks are studied with the SU(3) flavor symmetry in this work. We obtain the amplitude relations between different decay modes by the SU(3) irreducible representation approach, and then predict relevant branching ratios by present experimental data within $1 sigma$ error. We find that the predictions for all branching ratios except $mathcal{B}(Xirightarrow Lambda^0pi)$ and $mathcal{B}(Xi^*rightarrow Xipi)$ are in good agreement with present experimental data, that implies the neglected $C_+$ terms or SU(3) breaking effects might contribute at the order of a few percent in $Xirightarrow Lambda^0pi$ and $Xi^*rightarrow Xipi$ weak decays. We predict that $mathcal{B}(Xi^{-}rightarrow Sigma^0mu^-bar{ u}_mu)=(1.13pm0.08)times10^{-6}$, $mathcal{B}(Xi^{-}rightarrowLambda^0mu^-bar{ u}_mu)=(1.58pm0.04)times10^{-4}$, $mathcal{B}(Omega^-rightarrowXi^0mu^-bar{ u}_mu)=(3.7pm1.8)times10^{-3}$, $mathcal{B}(Sigma^-rightarrow Sigma^0e^-bar{ u}_e)=(1.35pm0.28)times10^{-10}$, $mathcal{B}(Xi^-rightarrow Xi^0e^-bar{ u}_e)=(4.2pm2.4)times10^{-10}$. We also study $T_{10}to T_8 P_8$ weak, electromagnetic or strong decays. Some of these decay modes could be observed by the BESIII, LHCb and other experiments in the near future. Due to the very small life times of $Sigma^0$, $Xi^{*0,-}$, $Sigma^{*0,-}$ and $Delta^{0,-}$, the branching ratios of these baryon weak decays are only at the order of $mathcal{O}(10^{-20}-10^{-13}$), which are too small to be reached by current experiments. Furthermore, the longitudinal branching ratios of $T_{8A} to T_{8B} ell^- bar{ u}_ell~(ell=mu,e)$ decays are also given.
In this contribution we compute some nonleptonic and semileptonic decay widths of $B_s$ mesons, working in the context of constituent quark models cite{Albertus:2014gba, Albertus:2014bfa}. For the case of semileptonic decays we consider reactions leading to kaons or different $J^pi$ $D_s$ mesons. The study of nonleptonic decays has been done in the factorisation approximation and includes the final states enclosed in Table 2.
A previous analysis of two-body Cabibbo allowed nonleptonic decays of $D^0$ mesons and of Cabibbo allowed and first-forbidden decays of $D^+$ and $D_s^+$ has been adjourned using more recent experimental data and extended to the Cabibbo forbidden decays of $D^0$. Annihilation and W-exchange contributions as well as final state interaction effects (assumed to be dominated by nearby resonances) have been included and are in fact crucial to obtain a reasonable agreement with the experimental data, which show large flavour SU(3) violations. New fitting parameters are necessary to describe rescattering effects for Cabibbo forbidden $D^0$ decays, given the lack of experimental informations on isoscalar resonances. We keep their number to a minimum - three - using phenomenologically based considerations. We also discuss CP violating asymmetries.
We provide a comprehensive test of factorization in the heavy-heavy $B$ decays motivated by the recent experimental data from BELLE and BABAR collaborations. The penguin effects are not negligible in the B decays with two pseudoscalar mesons. The direct CP asymmetries are found to be a few percent. We give estimates on the weak annihilation contributions by analogy to the observed annihilation-dominated processes. The $N_c$ insensitivity of branching ratios indicates that the soft final state interactions are not dominant. We also study the polarizations in $Bto D^*D_{(s)}^*$ decays. The power law shows that the transverse perpendicular polarization fraction is small. The effects of the heavy quark symmetry breaking caused by the perturbative QCD and power corrections on the transverse polarization are also investigated.