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相关论文: Gluonic Penguins in $B\to\pi\pi$ from QCD Light-Co…

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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…

高能物理 - 唯象学 · 物理学 2009-10-28 A. Khodjamirian , R. Rückl

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…

高能物理 - 唯象学 · 物理学 2009-11-10 Andrzej J. Buras , Robert Fleischer , Stefan Recksiegel , Felix Schwab

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…

高能物理 - 唯象学 · 物理学 2009-11-11 C. S. Kim , Sechul Oh , Chaehyun Yu

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…

高能物理 - 唯象学 · 物理学 2020-01-28 Nico Gubernari , Ahmet Kokulu , Danny van Dyk

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…

高能物理 - 唯象学 · 物理学 2007-05-23 Y. -Y. Keum

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…

高能物理 - 唯象学 · 物理学 2009-11-11 G. G. Ovanesyan , M. I. Vysotsky

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…

高能物理 - 唯象学 · 物理学 2008-11-26 J. Charles , A. Hocker , H. Lacker , S. Laplace , F. R. Le Diberder , J. Malcles , J. Ocariz , M. Pivk , L. Roos

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…

高能物理 - 唯象学 · 物理学 2007-05-23 Patricia Ball

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…

高能物理 - 唯象学 · 物理学 2009-09-25 G. Kramer , W. Palmer , Y. L. Wu

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…

高能物理 - 唯象学 · 物理学 2007-05-23 A. Khodjamirian , R. Rückl

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…

高能物理 - 唯象学 · 物理学 2009-11-07 A. Szczurek , N. N. Nikolaev , J. Speth

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…

高能物理 - 唯象学 · 物理学 2009-11-11 Alexander Khodjamirian , Thomas Mannel , Nils Offen

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…

高能物理 - 唯象学 · 物理学 2008-11-26 Fang Su , Yue-Liang Wu , Ya-Dong Yang , Ci Zhuang

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…

高能物理 - 唯象学 · 物理学 2009-10-31 T. Hambye , G. O. Koehler , E. A. Paschos , P. H. Soldan , W. A. Bardeen

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…

核理论 · 物理学 2009-10-31 Hungchong Kim , Su Houng Lee , Makoto Oka

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…

高能物理 - 唯象学 · 物理学 2009-10-09 M. Beneke , G. Buchalla , M. Neubert , C. T. Sachrajda

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…

高能物理 - 格点 · 物理学 2025-07-31 Tian Lin , Mattia Bruno , Xu Feng , Lu-Chang Jin , Christoph Lehner , Chuan Liu , Qi-Yuan Luo

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…

高能物理 - 唯象学 · 物理学 2008-11-26 Seungwon Baek

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…

高能物理 - 唯象学 · 物理学 2008-11-26 Hai-Yang Cheng , Kwei-Chou Yang

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…

高能物理 - 唯象学 · 物理学 2015-06-04 Aoife Bharucha