Phenomenological Applications of QCD Factorization to Semi-inclusive B Decays

We have systematically investigated the semi-inclusive B decays $B\to MX$, which are manifestations of the quark decay $b \to Mq$, within a framework inspired by QCD-improved factorization. These decays are theoretically clean and have distinctive experimental signatures. We focus on a class of these that do not require any form factor information and therefore may be especially suitable for extracting information on the angles $\alpha$ and $\gamma$ of the unitarity triangle. The strong phase coming from final-state rescattering due to hard gluon exchange between the final states can induce large rate asymmetries for tree-dominated color-suppressed modes $(\pi^0,\rho^0,\omega)X_{\bar s}$. The nonfactorizable hard spectator interactions in the 3-body decay $B\to Mq_1\bar q_2$, though phase-space suppressed, are extremely important for the tree-dominated modes $(\pi^0,\rho^0,\omega)X_{\bar s},~\phi X$, $J X_s,J X$ and the penguin-dominated mode $\omega X_{s\bar s}$. Our result for ${\cal B}(B\to J X_s)$ is in agreement with experiment. $B^0_s\to (\pi^0,\rho^0,\omega)X_{\bar s}$, $\rho^0X_{s\bar s}$, $B^0\to(K^-X,K^{*-}X)$ and $B^-\to (K^0X_s,K^{*0}X_s)$ are the most promising ones in searching for direct CP violation: they have branching ratios of order $10^{-6}-10^{-4}$ and CP rate asymmetries of order $(10-40)$.Comment: 12 pages, talk given at International Conference on Flavor Physics, Zhang-Jia-Jie City, Hunan, China, 31 May - 6 June, 200

Hadronic Two-Body Charmless B Decays

Implications of recent CLEO measurements of hadronic charmless B decays are discussed.Comment: 7 pages, invited talk presented at the Third International Conference on B Physics and CP Violation, Dec. 3-7, Taipe

Charmed Baryons Circa 2015

This is basically the update of [arXiv:0809.1869], a review on charmed baryon physics around 2007. Topics of this review include the spectroscopy, strong decays, lifetimes, nonleptonic and semileptonic weak decays, and electromagnetic decays of charmed baryons.Comment: 39 pages, 7 figures. References added and Table XIV updated, to appear in Frontiers of Physic

Weak Annihilation and the Effective Parameters a_1 and a_2 in Nonleptonic D Decays

Based on SU(3) flavor symmetry, many of the quark-graph amplitudes in two-body nonleptonic decays of charmed mesons can be extracted from experiment, which enable us to see the relevance and importance of weak annihilation topologies and to determine the complex parameters $a_1$ and $a_2$ to test the factorization approach. It is found that $a_2$ in $D\to \bar K^*\pi$ and $D\to \bar K\rho$ can be different by a factor of 2, indicating that nonfactorizable corrections to the latter are far more important than the former. The relative phase between $a_1$ and $a_2$ is about $150^\circ$. Weak annihilation topologies induced by nearby resonances via final-state rescattering can be described in a model-independent manner. Although the W-exchange contribution in $D\to PP$ decays is dominated by resonant final-state interactions (FSIs), its amplitude in VP decays (V: vector meson, P: pseudoscalar meson) receives little contributions from FSIs in the quark-antiquark resonance formation. As a consequence, the sign flip of the W-exchange amplitude in $D\to\bar K^*\pi$ and $\bar K\rho$ decays, which is needed to explain the relatively real decay amplitudes of $D\to \bar K\rho$, remains unexplained. SU(3) symmetry is badly broken in some Cabibbo-suppressed modes and it can be accounted for by the accumulation of some modest SU(3) violation in individual quark-graph amplitudes.Comment: 29 pages, 3 figures. The Close-Lipkin description of D-> K\rho decays is added and discusse