Related papers: $B \to \eta' X_s$ in the Standard Model

We study $B \to \eta' X_s$ within the framework of the Standard Model. Several mechanisms such as $b \to \eta' s g$ through the QCD anomaly, and $b \to \eta's $ and $B\to \eta' s \bar q$ arising from four-quark operators are treated…

We compute the branching ratio of inclusive $B \to \eta' X_s$ decay based upon the QCD anomaly mechanism: $b\to s+g^*\to s+g+\eta'$. To obtain a reliable $B \to \eta' X_s$ branching ratio, we calculate the $b\to s+g^*$ form factors up to…

Mechanisms for the observed large $Br(B \to \eta' +X_s)$ are examined. We propose that the dominant fraction of the $B \to \eta' +X_s$ rate is due mainly to $b \to s g^*$, where $g^*$ is an off-shell gluon, followed by $g^* \to g\eta'$ via…

We present updated and comprehensive Standard Model predictions for the inclusive rare decay $B \to X_s \nu\bar{\nu}$. Using a state-of-the-art determination of the short-distance coefficient, including NLO QCD and electroweak effects, and…

We present the QCD corrections to the matching conditions of the Delta B =1 magnetic and chromo-magnetic operators in the Standard Model and in two-Higgs doublet models. We use an off-shell matching procedure which allows us to perform the…

In this talk I discuss two topics related to B decays. I will first discuss the Standard Model prediction for $B\to \eta' X_s$, and then discuss how to use experimental information from $B\to J/\psi K^*$ to test CP violation beyond the SM.

Standard model factorization can account for the large rate for $B^\pm \to \eta' K^\pm$. The large rate for $B \to \eta' X_s$ is more problematic and requires a ``cocktail'' solution. Individual contributions from factorization, $b \to…

In this contribution the QCD next-to-next-to-leading order (NNLO) matching coefficients to the branching ratio $B_s \to \mu^+ \mu^-$ in the Standard Model (SM) and to $\bar{B}\to X_s \gamma$ in the Two Higgs Doublet Model (2HDM) are…

The charm content in $\eta'$ is estimated using the QCD U(1) axial anomaly applied to $b\to s g g \to \eta' s$. We find $f_{\eta'}^{(c)} \approx - 3.1$ MeV for $m_c = 1.3$ GeV. Our estimate agrees with other independent methods by Feldmann…

The next--to--leading order predictions for the branching ratio BR(B -> X_s gamma) are given in a generalized class of two Higgs doublets models. Included are the recently calculated leading QED corrections. It is shown that the high…

We give a summary about the various contributions which have to be calculated in order to obtain the next-to-leading logarithmic result for the branching ratio $BR(B \to X_s \gamma)$. Combining all these ingredients, which were obtained by…

We present an updated next-to-leading order analysis of the B -> X_s gamma branching ratio and photon spectrum, including consistently the effects of Fermi motion in the heavy-quark expansion. For the Standard Model, we obtain B(B -> X_s…

Using the $B_s$ meson wave function extracted from non-leptonic $B_s$ decays, we evaluate the short distance contribution of rare decays $B_s\to \ell^+\ell^-\gamma(\ell=e,\mu)$ in the standard model, including all the possible diagrams. We…

In this letter we revisit the Standard Model predictions for $\mathcal{B}(B\to K^{(\ast)}\nu\bar{\nu})$ and discuss the opportunities that open up when combining its partial decay rate with that of $B\to K^{(\ast)}\ell\ell$. In the Standard…

We have studied charmless two-body B decays involving $\eta$ and $\eta'$ in the framework of QCD improved factorization appraoch. The spectator hard scattering mechanism for $\eta'$ production have been re-examined and extended, which…

We review and update the branching ratios for the $B \to (\rho,\omega) \gamma$ decays, calculated in the QCD factorization approach in the next-to-leading order (NLO) in the strong coupling $\alpha_s$ and to leading power in $\Lambda_{\rm…

We propose a mechanism which can explain the large BR(B-> X_s eta')~ 10^(-3) observed by CLEO. In this mechanism, eta' is produced by the fusion of two gluons, one from QCD penguin b->sg and the other one emitted by the light quark inside…

We study the loop induced rare decays $B_s(B_d)\to\gamma\nu\bar\nu$ within the standard model. Both constituent quark model and pole model are used and the branching ratios turn out to be of the orders of $10^{-8}$ for $B_s\to \gamma \nu…

These lectures review some of the progress made in the quantitative understanding of B decays. The emphasis here is on applications of QCD using perturbative and non-perturbative techniques. In some cases, however, phenomenological models…

The theoretical status of NNLO QCD corrections to the inclusive radiative anti-B -> X_s gamma decay in the standard model is briefly overviewed. Emphasis is put on recent results for three-loop fermionic corrections to matrix elements of…