相关论文: B--> eta' X_s in the Standard Model

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…

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…

The gluino-induced contributions to the decay b-> s gamma are investigated in supersymmetric frameworks with generic sources of flavour violation. It is shown that, when QCD corrections are taken into account, the relevant operator basis of…

By employing the perturbative QCD (PQCD) factorization approach, we studied the sixteen $B/B_s \to \eta_c (\pi, K, \eta^{(\prime)},\rho,K^*,\omega,\phi)$ decays with the inclusion of the currently known next-to-leading order (NLO)…

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…

We perform a model-independent fit of the short-distance couplings $C_{7,9,10}$ within the Standard Model set of $b\to s\gamma$ and $b\to s\bar\ell\ell$ operators. Our analysis of $B \to K^* \gamma$, $B \to K^{(*)} \bar\ell\ell$ and $B_s…

The observables epsilon_K and Delta M_K play a prominent role in particle physics due to their sensitivity to new physics at short distances. To take advantage of this potential, a firm theoretical prediction of the standard-model…

In this contribution, the recent calculation of next-to-next-to-leading order QCD and next-to-leading order electroweak corrections to the decay $B_s\to \mu^+\mu^-$ is reviewed, and a detailed discussion of the uncertainty of the theory…

In this talk an analysis of the rare exclusive $B$ decays $B\to K\nu\bar\nu$ and $B\to K^{*}\nu\bar\nu$ within and beyond the Standard Model is presented. Combining new form factor determinations from lattice QCD with light-cone sum rule…

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…

The inclusive rate and forward-backward asymmetry of dilepton angular distribution for a B-meson to decay to strange hadronic final states and a $\tau^+\tau^-$ pair in a two Higgs doublet model are computed. In particular, contributions of…

We compute next-to-next-to-leading order QCD corrections to the partonic processes $b\to c \bar{u} d$ and $b\to c \bar{c} s$, which constitute the dominant decay channels in standard model predictions for $B$-meson lifetimes within the…

We report on the calculation of next-to-next-to-leading order (NNLO) QCD corrections to the width difference $\Delta \Gamma_s$ in the neutral $B$-meson mixing process $B^0_s - \bar{B}^0_s$. These contributions represent an important step in…

We analyze the rare semileptonic $B_s \to (\eta, \eta') l^+ l^-$, $(l=e, \mu, \tau)$ and $B_s \to (\eta, \eta') \nu \bar{\nu}$ transitions probing the $\bar s s$ content of the $\eta$ and $\eta'$ mesons via three--point QCD sum rules. We…

The decay $B \to X_s \gamma$ is studied at the Next to Leading Order in QCD in a class of models containing at least two Higgs doublets and with only one charged Higgs boson non-decoupled at low-energy. The two-loop matching condition is…

In this paper, we calculate the next-to-next-to-leading-order (NNLO) QCD corrections to $e^+e^- \to J/\psi+\eta_c$ at the $B$ factories. After including the NNLO corrections, the cross section of $e^+e^- \to J/\psi+\eta_c$ is enhanced by…

A theory of the B -> K \eta' decay is proposed. It is based on the Cabbibo favored b -> \bar{c} c s process followed by a direct materialization of the \bar{c} c pair into the \eta'. This mechanism works due to a non-valence Zweig rule…

We calculate the QCD corrected effective Hamiltonian for $B\bbar$--Mixing in heavy quark effective theory including corrections of the order $\Lambda_{QCD} / m_b$. The matrix elements of the subleading operators are estimated using the…

We present a calculation of the process B --> D eta' within a heavy-light chiral quark model. We assume that the eta' has a large gluonic component, and its coupling is described via the glue-glue-eta' effective vertex. The main…

We study the differential branching ratio, branching ratio and the CP-violating asymmetry for the exclusive $B_{d}->(\eta, \eta^{\prime}) \ell^+ \ell^-$ decays in the standard model. We deduce the $B_{d}->(\eta, \eta^{\prime})$ form factors…