相关论文: Electromagnetic penguin operators and direct CP vi…

The CP-violating charge asymmetry in decays K+- --> \pi+- \gamma\gamma, which is induced by the electromagnetic penguin operators, has been studied both in thestandard model and in its extensions. Because of a large enhancement of the…

We consider the chargino contribution to the CP violation in $B \to \phi K_S$ decay in the minimal supersymmetric standard model at large $\tan\be$. It is shown that the Wilson coefficient $C_{8g}$ of the chromomagnetic penguin operator can…

We consider the chargino contribution to the CP violation in B \to \phi K_S decay in the minimal supersymmetric standard model at large \tan\beta. It is shown that the Wilson coefficient C_{8g} of the chromomagnetic penguin operator can be…

We present results for the \Delta S=2 matrix elements which are required to study neutral kaon mixing in the standard model (SM) and beyond (BSM). We also provide leading chiral order results for the matrix elements of the electroweak…

It is shown that the K -> pi pi matrix elements of the four-quark operator Q_7, generated by the electroweak penguin-like diagrams of the Standard Model, can be calculated to first non-trivial order in the chiral expansion and in the 1/Nc…

We calculate the new contribution to the direct CP-violation parameter $\epsilon'$ in $K\to \pi\pi$ decay in the minimal left-right symmetric model with the recently-obtained right-handed quark Cabibbo-Kobayashi-Maskawa mixing. We pay…

The direct CP asymmetry $a_{CP}^{\mathrm{dir}}(D^0\rightarrow K_SK_S)$ involves exchange diagrams which are induced at tree level in the Standard Model. Since the corresponding topological amplitude $E_{KK}$ can be large, $D^0\rightarrow…

An analysis of the CP violating asymmetry in $K^\pm \to (3\pi)^\pm$ decays in the Standard Model and, by means of the mass insertion approximation, in a wide class of possible supersymmetric extensions, is presented. We find that the…

CP violation due to interference between $K_L$ and $K_S$ decays into $\pi ^+\pi^-\gamma$ is analyzed in the Standard Model. The CP-violating parameter $\epsilon'_{+- \gamma}$, which is the difference between $\eta_{+-\gamma}$ and…

We present the first QCD-based calculation of hadronic matrix elements with penguin topology determining direct CP-violating asymmetries in $D^0\to \pi^-\pi^+$ and $D^0\to K^- K^+$ nonleptonic decays. The method is based on the QCD…

We present results for Delta I=3/2 and Delta S=2 matrix elements relevant for CP violation in K->Pi Pi decays and for the K_S-K_L mass difference in the standard model and beyond. They were obtained with Neuberger fermions on quenched gauge…

We study the direct CP violation effect in the decay mode $B^+ \to \phi K^+$. This decay mode is dominated by the loop induced $\bar b \to \bar s s \bar s$ penguin diagram with a tiny contribution from annihilation diagram. Therefore, the…

We present an analysis of the enhancement of CP-violating charge asymmetries in $K \rightarrow 3\pi$ decays. Calculations of decay amplitudes are performed on the basis of bosonized strong and weak Lagrangians derived from QCD-motivated…

We analyze the supersymmetric contributions to direct-CP-violating observables in $K \to \pi\pi\gamma$ decays induced by gluino-mediated magnetic-penguin operators. We find that $\epsp_{+-\gamma}$ and the differential width asymmetry of…

We study the effects of the MSSM contribution on B -> phi K decays using the perturbative QCD approach. In this approach, strong phases can be calculated, so that we can predict the values of CP asymmetries with the MSSM contribution. We…

LHCb, CDF and most recently Belle have observed a large difference between direct CP asymmetries in $D^0\to K^+K^-$ and $D^0\to\pi^+\pi^-$. We use the measured value of $\Delta A_{CP}$ to constrain the magnitude and strong phase of a…

We present the calculation of $K\to\pi\pi$ matrix elements of electroweak penguin operators {\it i.e.} $Q_7$ and $Q_8$. In the numerical simulation, we use the gauge configurations generated by the combination of $N_f=2$ domain-wall…

In the presence of large New Physics contributions to loop-induced b->s transitions, sizable direct CP violation in B-> phi K decays is expected on general grounds. We compute explicitly CP-violating effects using QCD factorization and find…

We extend in several respects our earlier work on O(p^2) corrections to matrix elements of the electroweak penguin operator O_{ewp}. First, to facilitate comparison with certain lattice studies we calculate O(p^2) corrections to…

We study the correlation between $\epe$ and $\Delta I=1/2$ rule in the framework of non-linear $\sigma$ model including scalar mesons. The matrix elements of QCD and Electroweak (EW) penguin operators are computed within factorization…