相关论文: Large electroweak penguin contribution in B --> K …
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…
The unitarity of the Cabibbo-Kobayashi-Maskawa (CKM) matrix has been well established by both direct and indirect measurements without any evidence of discrepancy. The CKM weak phase $\alpha$ is directly measured using an isospin analysis…
Latest experimental progress is reviewed on the searches for physics beyond the Standard Model using the radiative and electroweak penguin decays of B mesons. This review covers inclusive and exclusive measurements of the b --> s gamma, b…
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 analyze the rare decay mode $B \to \phi \pi $, which is a pure penguin induced process, receiving dominant contribution from the electroweak penguins. Thus the standard model branching ratio is expected to be very small, which makes it…
We present recent results for radiative and electroweak penguin decays of $B$ me son at Belle. Measurements of differential branching fraction, isospin asymmetr y, $K^*$ polarization, and forward-backward asymmetry as functions of $q^2$ for…
We consider penguin contributions to the lifetime splitting between the $B_s$ and the $B_d$ meson. In the Standard Model the penguin effects are found to be opposite in sign, but of similar magnitude as the contributions of the…
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…
We report improved measurements of branching fractions for B -> K pi and B -> pi pi decays based on a data sample of 449 million B Bbar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB e^+e^- collider. We…
Isospin structure of gluon mediated or strong penguin is significantly altered when the full electroweak corrections are included. This has the consequence that some previous analyses which relied on a simple isospin structure in charmless…
Recent branching fraction and asymmetry results of Electroweak Penguin B decays from BaBar, Belle and CLEO experiments are reviewed. While these branching fractions are consistent with the Standard Model expectations and are being used to…
In the presence of penguin contributions, the indirect CP asymmetry in B0(t)->pi+ pi- measures some effective (``polluted'') angle 2alpha_{eff}. The angle 2theta=2alpha_{eff}-2alpha, parameterizes the size of the penguin pollution. A new,…
An analysis of $B \to K\pi$ decays is given, assuming a small elastic $\pi K $ rescattering phase difference.Using factorization model only for the tree-level and electroweak penguin amplitudes, we show that the strong penguin amplitude,…
We analyse the B -> pi pi, pi K modes in the light of the most recent B-factory data, and obtain the following new results: (i) the B0 -> pi+ pi-, pi- K+ modes prefer gamma=(74+-6)deg, which - together with |V_ub/V_cb| - allows us to…
We analyze the possibility of observing new physics effects in the $b \to d$ penguin amplitudes. For this purpose, we consider the decay mode $B \to K^0 \bar K^0 $, which has only $b \to d$ penguin contributions. Using the QCD factorization…
We provide Standard Model expectations for the rare radiative decays B->K^* gamma, B->rho gamma and B-> omega gamma, and the electroweak penguin decays B->K^* l^+ l^- and B->rho l^+ l^- at the next-to-leading order (NLO), extending our…
The space-like penguin contributions to branching ratios and CP asymmetries in charmless decays of $B_{c}$ to two pseudoscalar mesons are studied using the next-to-leading order low energy effective Hamiltonian and factorization…
The pure annihilation type decays $B^0_d\to\phi\gamma$ and $B_s\to\rho\gamma$ receive only color suppressed penguin contributions with a very small branching ratio in the standard model. When we include the previously neglected…
Rare B decays of the type $b \to s~\ell^+\ell^-(\nu\bar\nu)$ are analyzed in a generic scenario where New Physics effects enter predominantly via $Z$ penguin contributions. We show that this possibility is both phenomenologically allowed…
Based on the most recent data in charmless B decays including the very recently reported large direct CP violations, it is shown that the weak phase gamma can well be extracted without two-fold ambiguity even only from two decay modes…