相关论文: Analysis of $B \to K\pi$ decays with small elastic…
The large branching ratios for $B \to K\pi$ decays as observed by the CLEO Collaboration indicate that penguin interactions contribute a major part to the decay rates and provide an interference between the Cabibbo-suppressed tree and…
We analyse the $B \to K\pi$ decays using the factorisation model with final state interaction phase shift included. We find that factorisation seems to describe qualitatively the latest CLEO data. For a test of the factorisation model, we…
Though QCD Factorization(QCDF) could produce sufficiently large $B\to K\pi$ branching ratios close to experiments, the predicted direct CP asymmetry in ${\bar B}^{0}\to K^{+}\pi^{-}$ decay is however still quite below experiment, even with…
The recently observed $B^-\to K^- \pi^0$, $\bar K^0 \pi^-$ and $\bar B^0 \to K^- \pi^+$ decay modes appear to have nearly equal branching ratios. This suggests that tree and electroweak penguins play an important role, and inclusion of the…
We study a relation between the weak phase $\gamma$ and the rates and CP asymmetries of several $K \pi$ decays of $B^+$, $B^0$, and $B_s$, emphasizing the impact of the latter measurements. Current data indicate large SU(3) breaking in the…
Recent results from CLEO on $B\to K\pi$ indicate that the phase $\gamma$ may be substantially different from that obtained from other fit to the KM matrix elements in the Standard Model. We show that $\gamma$ extracted using $B\to K\pi,…
We compute branching ratios of $B\to K\pi$ decays in the framework of perturbative QCD factorization theorem. Decay amplitudes are classified into the topologies of tree, penguin and annihilation, all of which contain both factorizable and…
Motivated by recent measurements, we investigate $B\to \pi \pi, K \pi$ decay modes in the framework of QCD improved factorization, which was recently proposed by Beneke $et al$. We find that all the measured branching ratios are well…
A general parametrization of the $B^+\to\pi^+ K^0$ and $B_d^0\to\pi^- K^+$ decay amplitudes is presented. It relies only on the isospin symmetry of strong interactions and the phase structure of the Standard Model and involves no…
Motivated by the recent experimental data, we have revisited the $B\to \pi K,\pi \pi$ decays in the framework of QCD factorization, with inclusion of the important strong penguin corrections of order $\alpha_s^2$ induced by $b\to D g^\ast…
The role of penguin amplitudes in CP violating $B$ decays is reviewed, emphasizing recent progress in the analysis of electroweak penguin contributions. It is shown how these terms are included in a model-independent manner when measuring…
The decays $B^\pm\to \pi^\pm K$ and $B_d\to \pi^\mp K^\pm$ were observed by the CLEO collaboration last year; they may play an important role to probe the angle $\gamma$ of the unitarity triangle of the CKM matrix. After a general…
We evaluate $B\to K\pi$ decay amplitudes in perturbative QCD picture. It is found that penguin contributions are dynamically enhanced by nearly 50% compared to those assumed in the factorization approximation. It is also shown that…
In the study of two-body charmless B decays as a mean of looking for direct CP-violation and measuring the CKM mixing parameters in the Standard Model, the short-distance penguin contribution with its absorptive part generated by charm…
We suggest a new technique to determine the CKM phase $\gamma$ {\em without} neglecting the (soft) final state rescattering effects. We use (time integrated) $B$ meson decay rates to $\pi$'s and $K$'s. A set of 5 $\Delta S = 0$ (or 1…
We present a method to measure the CKM phase $\alpha$ and the tree and penguin (strong and electroweak) amplitudes in $B \rightarrow \pi \pi$ decays, based on isospin consideration and the weak assumption that all tree amplitudes have a…
From a time-dependent analysis of the decay $B^0_{d} \to \pi^+ \pi^-$ and using a model-dependent $A_P/A_T$ ratio of the penguin-to-tree amplitudes contributing to the decay, both the weak phase $\alpha$ and the strong phase shift…
The ratio of partial decay rates for charged and neutral $B$ mesons to $K \pi$ final states provides information on the weak phase $\gamma \equiv {\rm Arg} (V_{ub}^*)$ when augmented with information on the CP-violating asymmetry in the…
The decay rates for $B^0 \to K^+ \pi^-$, $B^+ \to K^0 \pi^+$, and the charge-conjugate processes were found to provide information on the weak phase $\gamma \equiv {\rm Arg}(V_{ub}^*)$ when the ratio $r$ of weak tree and penguin amplitudes…
We calculate CP-violating rates and asymmetry parameters in charged and neutral $B\to \pi\pi, \pi K$ and $\bar K K$ decays arising from the interference of tree and penguin (strong and electroweak) amplitudes with different strong and CKM…