Related papers: QCD factorization for $\Lambda_b^0\to\Lambda_c^+\p…
The enhancement $\Delta \Gamma (\Lambda_b)$ of the $\Lambda_b$ decay rate due to four-fermion processes of weak scattering and Pauli interference is calculated within the quark model. An estimate of the relative $bu$ wave function at zero…
We provide updated predictions for the hadronic decays $\bar{B}_s^0\to D_s^{(*)+} \pi^-$ and $\bar{B}^0\to D^{(*)+} K^-$. They are based on $\mathcal{O}(\alpha_s^2)$ results for the QCD factorization amplitudes at leading power and on…
We discuss exclusive radiative decays in QCD factorization within the Standard Model. In particular, we consider the decays B -> V gamma, with a vector meson K* or rho in the final state, and the double radiative modes B_s -> gamma gamma…
We present a complete calculation of the Leading Order QCD corrections to the quark level decay amplitude for b -> s gamma gamma and study their relevance for both the inclusive branching ratio BR(B -> X_s gamma gamma) and for the exclusive…
As we pointed out recently, the neutral decays $B_d\to\pi^\mp K^\pm$ and $B_d\to\pi^0K$ may provide non-trivial bounds on the CKM angle $\gamma$. Here we reconsider this approach in the light of recent CLEO data, which look very…
The $B_{c}^{\ast}$ ${\to}$ $B_{u,d,s}V$, $B_{u,d,s}P$ decays are investigated with the QCD factorization approach, where $V$ and $P$ denote the ground $SU(3)$ vector and pseudoscalar mesons, respectively. The $B_{c}^{\ast}$ ${\to}$…
We give a more complete calculation of $b \to s e^+e^- $ decay including leading log QCD corrections from $m_{top}$ to $M_W$ in addition to corrections from $M_{W}$ to $m_b$. The differential decay rate is found to be slightly suppressed…
We present within the Standard Model the exclusive radiative decays B -> K*/rho gamma and B_(s/d) -> gamma gamma in QCD factorization based on the heavy-quark limit m_b >> Lambda_QCD. For the decays with a vector meson in the final state we…
For the vertex corrections to the partial decay rate $\Gamma(Z \to b\bar{b})$ involving the top quark only the leading terms of order $\alpha\alpha_s$ in the $1/M_t$ expansion are known. In this work we compute the missing next-to-leading…
We calculated the branch ratios of $\Lambda_C\to \Lambda K$ and $\Lambda_C\to \Lambda \pi$ within factorization approximation. It is found that the results suffers from the uncertainties of form factors. To reduce such uncertainties, we…
In previous work we have developed a relativistic quark model of mesons which is consistent with all QCD constraints at zeroth and first order in the heavy quark expansion. Here we obtain first order model predictions for the differential…
We present a new analysis of B_d,s -> KK modes within the SM, relating them in a controlled way through SU(3)-flavour symmetry and QCD-improved factorisation. We propose a set of sum rules for B_d,s -> K^0 \bar K^0 observables. We determine…
We present an analytic formula for the $O(\alpha_s)$ corrections to the decay $t\to H^+b$ for nonzero $m_H$ and $m_b$. The Equivalence Theorem is used to relate these corrections to those for the process $t\to W^+b$. Contrary to previously…
We investigate the ten independent local form-factors relevant to the $b$-baryon decay $\Lambda_b \to \Lambda \ell^+\ell^-$, combining information of lattice QCD and dispersive bounds. We propose a novel parametrization of the form factors…
In this paper, we firstly varify that the factorization hypothesis is valid for the exclusive process $\rho \gamma^{\star} \to \pi$ at the next-to-leading order (NLO) with the collinear factorization approach, and then extend this proof to…
The Lambda_b to Lambda_c semileptonic decay is analyzed in the framework of heavy quark effective theory to the order of 1/m_c and 1/m_b. The QCD sum rule and large N_c predictions to the decay form factors are applied. It argues that the…
We present a concise review of the recent theoretical progress concerning the standard model calculation of the inclusive radiative anti-B --> X(s) gamma decay. Particular attention is thereby devoted to the calculations of the…
A method, known as ``minimal renormalon subtraction'' [Phys. Rev. D 97 (2018) 034503, JHEP 2017 (2017) 62], relates the factorial growth of a perturbative series (in QCD) to the power~$p$ of a power correction $\Lambda^p/Q^p$. ($\Lambda$ is…
A variant of variationally optimized perturbation, incorporating renormalization group properties in a straightforward way, uniquely fixes the variational mass interpolation in terms of the anomalous mass dimension. It is used at three…
We obtain model independent bounds for the form factors which arise in semileptonic B -> Pi decays. To this end we derive a theoretical restriction for possible combinations of the value of the form factor and its derivatives at the…