相关论文: Penguins in B decays
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…
A major goal in B physics is measuring the CP-violating asymmetry in the decay $B^0 \rightarrow \pi^+ \pi^-$. In order to determine one of the phase angles in the CKM matrix from this decay it is necessary to determine the influence of the…
We study the penguin pollution in the B^0 -> J/psi K_S decay up to leading power in 1/m_b and to next-to-leading order in \alpha_s, m_b being the b quark mass and \alpha_s the strong coupling constant. The deviation \Delta S_{J/psi K_S} of…
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,…
Penguin, or loop, decays of B mesons induce effective flavor-changing neutral currents, which are forbidden at tree level in the Standard Model. These decays give special insight into the CKM matrix and are sensitive to non-standard model…
We discuss a novel electromagnetic penguin contribution to the transverse helicity amplitudes in B decays to two vector mesons, which is enhanced by two powers of mB/Lambda relative to the standard penguin amplitudes. This leads to unique…
Major new experimental efforts on detecting CP violation in $B$ decays will very soon go on the air. Recent developments suggest that final state interaction phases in exclusive decays of $B$ are unlikely to be small indicating the…
The influence of strong and electroweak penguin amplitudes in $B/ \bar B \rightarrow \pi^+\pi^-$ is investigated in connection with the determination of the unitarity triangle angle $\alpha$ of the CKM matrix. A relation between the…
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…
Over the last two decades, $B \to \pi K$ modes have received a lot of attention. They are particularly interesting since the main contribution to these decays comes from QCD penguin topologies. Furthermore, electroweak penguin amplitudes…
We present the most complete analysis of the penguin correction to the extraction of the standard-model parameter sin(2\phi_1) from the B^0 -> J/psi K_S decay up to leading power in 1/m_b and to next-to-leading order in \alpha_s, \phi_1…
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…
Measurements of the combined branching ratios for $B^\pm \to \pi^\pm K$ and $B_d \to \pi^\mp K^\pm$ allow interesting constraints on the CKM angle $\gamma$, the ratio $r \equiv |T'|/|P'|$ of the current-current and penguin operator…
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…
An enhanced electroweak penguin amplitude due to the presence of unknown new physics can explain the discrepancies found between theory and experiment in the B -> pi K decays, in particular in A_CP(B^- -> pi^0 K^-) - A_CP(\bar{B}^0 -> pi^+…
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…
For about twenty years, $B\to\pi K$ decays are in the focus of $B$-decay studies. We show that a correlation between the CP asymmetries of $B^0_d\to\pi^0K_{\rm S}$ reveals a tension with the Standard Model. Should it be due to New Physics,…
The mixing-induced CP asymmetries in $B_d \to J/\psi K_S$ and $B_s \to J/\psi \phi$ are essential to detect or constrain new physics in the $B_d\! - \overline{\!B}{}_d$ and $B_s\! - \overline{\!B}{}_s$ mixing amplitudes, respectively. To…
We present strategies for determining electroweak penguins from experimental data. Using the CKM-angle $\gamma$ as one of our central inputs and making some reasonable approximations, we show that the $\bar b\to\bar s$ electroweak penguin…
Radiative penguin decays provide an indirect probe for physics beyond the Standard Model and contribute to the determination of the CKM matrix elements. Copious quantities of B mesons produced at the B-Factories permit precision…