相关论文: How Penguins Started to Fly

We reanalyze the decay $B_d\to\pi^+\pi^-$ without assuming dominance of QCD penguins with internal top-quark exchanges. In that case the weak phase of the $\bar b \to\bar d$ QCD penguin amplitude is not related in a simple way to the CKM…

We make an attempt to clarify the role of the annihilation or "penguin" mode in the description of the $K\rightarrow\pi\pi$ decay within the Standard Model. The attention is concentrated on new operators in the effective $\Delta S=1$…

B-meson decays play an important role in flavour physics. The $B \rightarrow \pi K$ decays are dominated by QCD loop diagrams (penguins) but also electroweak penguins, where New Physics may enter, have a significant impact on the decay…

Contributions of low energy "eye" and "figure-eight" quark diagrams to the $K \rightarrow \pi$ weak transitions are studied in a hadron- level phenomenological approach. It is shown that these contributions may be estimated by considering…

The high precision to which the standard model has been confirmed implies that new physics effects have to be small in the observed processes. Together with the outstanding precision expected from present and future collider experiments…

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 evaluate the decays B => K* pi, K (rho,omega,phi) adding the long distance charming penguin contributions to the short distance: Tree+Penguin amplitudes. We estimate the imaginary part of the charming penguin by an effective field theory…

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…

Strategies for extracting CKM phases from non-leptonic $B$ decays are reviewed briefly. Both general aspects and some recent developments including CP-violating asymmetries, the $B_s$ system in light of a possible width difference…

We accomplish the analytical computation of the pure weak annihilation non-leptonic $B$-meson decay amplitudes at leading power in the heavy quark expansion. The novel observation regarding such fundamental hadronic quantities is that…

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…

In the absence of the QCD penguin contributions a measurement of the time-dependent asymmetry in the decay $B^0(t)\to \pi^+\pi^-$ gives directly the weak angle $\alpha$. Several bounds have been proposed in the literature on the magnitude…

We discuss the role of electroweak penguins in $B$ decays to two light pseudoscalar mesons. We confirm that the extraction of the weak phase $\alpha$ through the isospin analysis involving $B\to\pi\pi$ decays is largely unaffected by such…

We present the current wisdom regarding the measurement of the CP-violating phases of the CKM unitarity triangle in $B$-meson decays. After an introduction to the SM picture of CP violation, we review direct and indirect CP violation, the…

In charmless nonleptonic B decays to \pi\pi or \rho\rho, the "color allowed" and "color suppressed" tree amplitudes can be studied in a systematic expansion in \alphas(mb) and \Lambda/mb. At leading order in this expansion their relative…

It is argued that, in the presence of soft final-state interactions, the diagrammatic amplitude approach adopted in many analyses of hadronic B decays into light mesons can be misleading when used to deduce the unimportance of certain decay…

We discuss a possibility of large electroweak(EW) penguin contribution in B-->K pi and pi pi. The recent experimental data may be still suggesting that there are some discrepancies between the data and theoretical estimations. In B --> K pi…

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…

Long-distance contributions of operators of the effective non-leptonic weak Hamiltonian containing charmed currents have been recently studied. Penguin-like contractions of these operators, denoted as charming penguins, have been shown to…

In the recent literature, constraints on the CKM angle $\gamma$ arising from the branching ratios for $B^\pm\to\pi^\pm K$ and $B_d\to\pi^\mp K^\pm$ decays received a lot of attention. An important theoretical limitation of the accuracy of…