相关论文: Gluonic Penguins in $B\to\pi\pi$ from QCD Light-Co…
We present results for the $B \rightarrow \pi$ and $D\rightarrow \pi$ form factors derived from QCD sum rules on the light-cone. Our predictions are compared with experiment and used to extract the quark mixing parameter $|V_{ub}|$ from a…
The recent observation of B_d -> pi^0 pi^0 at the B factories with a surprisingly large branching ratio represents a challenge for theory, and complements the amazingly small B_d -> pi^+ pi^- rate. We point out that all puzzling B -> pi pi…
In the light of new experimental results on B -> K pi decays, we critically study the decay processes B -> K pi in a phenomenological way. Using the quark diagram approach and the currently available data, we determine the allowed values of…
We provide results for the full set of form factors describing semileptonic $B$-meson transitions to pseudoscalar mesons $\pi$, $K$, $\bar{D}$ and vector mesons $\rho$, $K^*$, $\bar{D}^*$. Our results are obtained within the framework of…
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…
The hypothesis of the smallness of penguin contribution to charmless strangeless $B_d (\bar B_d)$ decays allows to determine with high accuracy the value of angle $\alpha$ from the currently available $B \to \rho\rho$, $B \to \pi\pi$ and…
We update the profile of the CKM matrix. The apex (rhobar,etabar) of the Unitarity Triangle is given by means of a global fit. We propose to include therein sin2alpha from the CP-violating asymmetries in B0->rho+rho-, using isospin to…
I calculate the form factors describing semileptonic and penguin induced decays of B mesons into light pseudoscalar and vector mesons. The form factors are calculated from QCD sum rules on the light-cone including contributions up to twist…
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…
We review QCD sum rule applications to hadronic matrix elements of exclusive $B$ and $D$ decays. Results are presented for the form factors $f^+$ and $F_0$ of $B \rightarrow \pi$ and $D\rightarrow \pi$ transitions. The predictions are used…
We discuss the onset of the dominance of the Glauber-Gribov-Landshoff (GGL) component of pQCD hard two-gluon (2G) exchange contribution to hard elastic $\pi\pi$ scattering at moderate energies . Such a hard $\pi\pi$ scattering could via…
Employing the light-cone sum rule approach in QCD, we relate the $B$-meson distribution amplitude to the $B\to \pi$ form factor at zero momentum transfer. In leading order, the sum rule is converted into a simple expression for the inverse…
The branching ratios and CP violations of the $B\to D\pi$ decays, including both the color-allowed and the color-suppressed modes, are investigated in detail within QCD framework by considering all diagrams which lead to three effective…
We calculate long-distance contributions to the amplitudes A(K^0 --> pi pi, I) induced by the gluon and the electroweak penguin operators Q_6 and Q_8, respectively. We use the 1/N_c expansion within the effective chiral lagrangian for…
In the conventional QCD sum rule calculation for the $\pi NN$ coupling beyond the soft-pion limit, there are three distinct Dirac structures, each of which can be used to construct separate sum rule. We point out subtleties in the previous…
We show that the factorization formula for non-leptonic B decays to two light flavor non-singlet mesons derived by Bauer et al. in the context of soft-collinear effective theory is equivalent to the corresponding formula in the QCD…
We develop a method to compute the pion transition form factor directly at arbitrary space-like photon momenta and use it to determine the $\pi^0$-pole contribution to the hadronic light-by-light scattering in the anomalous magnetic moment…
The large ratio of color-suppressed tree amplitude to color-allowed one in $B \to \pi \pi$ decays is difficult to understand within the Standard Model, which is known as the "$B \to \pi\pi$ puzzle". The two tree diagrams contain the up- and…
Weak radiative baryonic B decays $B\to\B_1\ov \B_2\gamma$ mediated by the electromagnetic penguin process $b\to s\gamma$ have appreciable rates larger than their two-body counterparts $B\to\B_1\ov \B_2$. The branching ratios for…
We calculate the leading-twist O(alphas^2 beta0) corrections to the B to pi transition form factor f+(0) in light-cone sum rules. We find that, as expected, there is a cancellation between the O(alphas^2 beta0) corrections to fB f+(0) and…