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A calculation of the leading isospin-breaking contributions to the B -> K^* gamma decay amplitudes based on the QCD factorization approach is presented. They arise at order Lambda/m_b in the heavy-quark expansion and are due to annihilation…

High Energy Physics - Phenomenology · Physics 2014-11-17 Alexander L. Kagan , Matthias Neubert

In the study of two-body charmless B decays as a mean of looking for direct CP-violation and measuring the CKM mixing parameters in the Standard Model, the short-distance penguin contribution with its absorptive part generated by charm…

High Energy Physics - Phenomenology · Physics 2009-11-07 T. N. Pham

In the absence of the QCD penguin contributions a measurement of the time-dependent asymmetry in the decay $B^0(t)\to \pi^+\pi^-$ gives directly the weak angle $\alpha$. Several bounds have been proposed in the literature on the magnitude…

High Energy Physics - Phenomenology · Physics 2009-10-31 Dan Pirjol

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…

High Energy Physics - Phenomenology · Physics 2016-09-06 M. Ciuchini , E. Franco , G. Martinelli , L. Silvestrini

It is argued that, in the presence of soft final-state interactions, the diagrammatic amplitude approach adopted in many analyses of hadronic B decays into light mesons can be misleading when used to deduce the unimportance of certain decay…

High Energy Physics - Phenomenology · Physics 2010-11-23 Matthias Neubert

Long-distance contributions of operators of the effective non-leptonic weak Hamiltonian containing charmed currents have been recently studied. Penguin-like contractions of these operators, denoted as charming penguins, have been shown to…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Ciuchini , R. Contino , E. Franco , G. Martinelli , L. Silvestrini

In charmless nonleptonic B decays to \pi\pi or \rho\rho, the "color allowed" and "color suppressed" tree amplitudes can be studied in a systematic expansion in \alphas(mb) and \Lambda/mb. At leading order in this expansion their relative…

High Energy Physics - Phenomenology · Physics 2014-11-18 Yuval Grossman , Andreas Hocker , Zoltan Ligeti , Dan Pirjol

We discuss the determination of the CKM angle $\alpha$ using the non-leptonic two-body decays $B\to \pi\pi$, $B\to \rho\rho$ and $B\to \rho\pi$ using the latest data available. We illustrate the methods used in each case and extract the…

High Energy Physics - Phenomenology · Physics 2017-09-08 J. Charles , O. Deschamps , S. Descotes-Genon , V. Niess

We evaluate the decays B => K* pi, K (rho,omega,phi) adding the long distance charming penguin contributions to the short distance: Tree+Penguin amplitudes. We estimate the imaginary part of the charming penguin by an effective field theory…

High Energy Physics - Phenomenology · Physics 2014-11-17 C. Isola , M. Ladisa , G. Nardulli , P. Santorelli

Two-body charmless nonleptonic decays of the B_s meson are studied within the framework of generalized factorization in which factorization is applied to the tree level matrix elements while the effective Wilson coefficients are $\mu$ and…

High Energy Physics - Phenomenology · Physics 2016-08-25 Yaw-Hwang Chen , Hai-Yang Cheng , B. Tseng

Some rare hadronic decays of B mesons, such as B->pi K, are sensitive to isospin-violating contributions from physics beyond the Standard Model. Although commonly referred to as electroweak penguins, such contributions can often arise…

High Energy Physics - Phenomenology · Physics 2009-10-31 Yuval Grossman , Alexander L. Kagan , Matthias Neubert

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…

High Energy Physics - Phenomenology · Physics 2010-11-01 A. Deandrea , N. Di Bartolomeo , R. Gatto , F. Feruglio , G. Nardulli

A clean determination of the angle $\alpha$ of the unitary triangle from $B\to \pi\pi$ decays requires an isospin analysis. If the $B \to \pi^0\pi^0$ and $\bar B \to \pi^0\pi^0$ decay rates are small it may be hard to carry out this…

High Energy Physics - Phenomenology · Physics 2010-11-23 Yuval Grossman , Helen R. Quinn

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…

High Energy Physics - Phenomenology · Physics 2010-11-01 Dongsheng Du , Zhi-zhong Xing

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…

High Energy Physics - Phenomenology · Physics 2008-11-26 Seungwon Baek

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…

High Energy Physics - Phenomenology · Physics 2009-11-11 G. G. Ovanesyan , M. I. Vysotsky

We show that the neglect of the $(V-A)\times (V+A)$ pieces of the electroweak penguin (EWP) amplitudes in the effective hamiltonian (the Wilson coefficients are very small) allows one to calculate the relative size of some tree and EWP…

High Energy Physics - Phenomenology · Physics 2007-05-23 Maxime Imbeault

We study the effects of electroweak penguin (EWP) amplitudes in $B$ meson decays into two charmless pseudoscalars in the approximation of retaining only the dominant EWP operators $Q_9$ and $Q_{10}$. Using flavor SU(3) symmetry, we derive a…

High Energy Physics - Phenomenology · Physics 2014-11-17 Michael Gronau , Dan Pirjol , Tung-Mow Yan

We summarize some persistent problems in scalar spectroscopy and discuss what could be learned here from charmless B-decays. Recent experimental results are discussed in comparison with theoretical expectations: a simple model based on…

High Energy Physics - Phenomenology · Physics 2009-11-11 Peter Minkowski , Wolfgang Ochs

Latest data on charmless strange vector-pseudoscalar $B^+$ decays now including $B^+\to \rho^+ K^o$ confirm a simple penguin model in which the gluon $G$ in an initial $\bar s u G$ state fragments equally into $u \bar u$, $d \bar d$ and $s…

High Energy Physics - Phenomenology · Physics 2007-05-23 Harry J. Lipkin