相关论文: Are "Penguins" Black-and-White?

Charmless B decay modes $B \to \pi \pi, \pi K$ and $KK$ aresystematically investigated with and without flavor SU(3) symmetry. Independent analyses on $\pi \pi$ and $\pi K$ modes both favor a large ratio between color-suppressed tree ($C$)…

The $b \to s$ penguin amplitude affects a number of $B$ meson decays to two pseudoscalar ($P$) mesons in which potential anomalies are being watched carefully, though none has yet reached a statistically compelling level. These include (a)…

We discuss all contributions from inelastic SU(3)-symmetric rescattering in B decays into a final pair of pseudoscalar mesons $PP = \pi \pi$, $K\bar{K}$, $\pi K$. FSI-induced modifications of amplitudes obtained from the quark-line approach…

New contributions to the short-distance b --> s eta' transition are considered. They correspond to the quark and gluon content of eta'. Although substantially larger than the referent QCD anomaly tail, they still cannot account for the…

We calculate $\Delta I = 3/2$ kaon decay matrix elements using domain wall fermions and the DBW2 gauge action at one coarse lattice spacing corresponding to $a^{-1} = 1.3$ GeV. We employ the Lellouch and L\"uscher formula and its extention…

We present estimates of the charming penguin contribution to B => K pi, pi pi,K eta, K eta' decays due to intermediate charmed meson states. We find that this contribution is indeed significant for B => K pi decays, and its inclusion,…

Recently, the standard model prediction of $\epsilon'/\epsilon$ was improved, and a discrepancy from the experimental results was reported at the $2.9\sigma$ level. We study the chargino contributions to $Z$ penguin especially with the…

Full expressions of the $B^0_d \to \pi^+ \pi^-$ and $B^0_d \to \pi^0 \pi^0$ amplitudes, given in terms of matrix elements of operators of the effective weak Hamiltonian, are used to study the dependence of the relevant branching ratios on…

We present a study of non-leptonic B-meson decays, partial widths and CP asymmetries, and discuss the possibilities of determining the penguin contributions through less model-dependent phenomenological analyses. In the last section we…

Firstly, I report on a recent work --carried out with T. Hambye and E. de Rafael-- on how to use the large-Nc expansion to calculate unfactorized contributions from the strong penguin operators, and their impact on observables such as…

Penguin diagrams for decays such as $b\to (s,d)\gamma$ involve virtual loops of $u$ or other light quarks. Logarithms of the virtual quark mass could, in principle, influence the phenomenological analysis of the decay. It is thus important…

QCD penguins are responsible for about 2/3 of the Delta I=1/2 rule in K to pi pi decays, as inferred from a combined analysis of K to pi pi and KL to gamma gamma. Further tests based on the decays KS to pi0 gamma gamma and K+ to pi+ gamma…

We analyze the effects of the space-like penguin diagrams in two body B decays $B^-\to K^-{\bar K}^0$ and $B^-\to \pi^-{\bar K}^0$. Special attention is paid to the operator $Q_6$, whose contribution is large in the BSW model, but vanishes…

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,…

The space-like penguin contributions were ignored on little ground in many previous studies of nonleptonic B decays and CP violation. Taking the penguin-dominated channels $B^{-} _{u}\rightarrow \bar{K}^{0}\pi$ and $B^{-}_{u}\rightarrow…

We calculate the contributions of penguin diagrams with internal u or c quarks to various inclusive charmless B-decay rates. Further we analyze the influence of the chromomagnetic dipole operator Q_8 on these rates. We find that the rates…

We present a detailed calculation of the contributions of charginos, scalar quarks, and charged Higgs boson to the $K^+\rightarrow \pi^+\nu\overline\nu$\ and $K^0_L\rightarrow\mu^+\mu^-$\ decays. We include mixings: that of charginos and…

In left-right models the gluonic penguin contribution to b --> s s-bar s transition is enhanced by m_t/m_b due to the presence of (V+A) currents and by the larger values of loop functions than in the Standard Model. Together those may…

We study CP violation and the contribution of the strong kaon-pion interactions in the three body B --> K pi+ pi- decays. We extend our recent work on the effect of the two-pion S- and P-wave interactions to that of the corresponding…

Dispersion approach based on the constituent quark picture and its applications to weak decays of heavy mesons are reviewed. Meson interaction amplitudes are represented within this approach as relativistic spectral integrals over the mass…