Related papers: $B \to \gamma \gamma$ in an ACD model
We discuss a simple method to evaluate the QCD corrections to $\Delta\rho$. It assumes that the perturbative expansion in terms of $\ms$ parameters is meaningful and, unlike other studies, exploits significant available information…
Recent advances in the calculation of the $b\to s\gamma$ decay branching ratio are presented in the context of supersymmetric theories. Theoretical accuracy increased by inclusion of the next-to-leading order QCD corrections makes it…
We report on recent theoretical progress in radiative B decays. We focus on a calculation of logarithmically enhanced QED corrections to the branching ratio and forward-backward asymmetry in the inclusive rare decay anti-B --> X(s) l+ l-,…
The interference between Cabibbo-favoured and Cabibbo-suppressed $B\to D\pi$ decay amplitudes provides sensitivity to the CKM angle $\gamma$. The relative size of the interfering amplitudes is an important ingredient in the determination of…
$B_s \to \rho(\omega) K^{\ast}$ are useful to determine the $B_s$ distribution amplitude, as well as constrain the CKM phase angle $\alpha$. We study these decays within the Perturbative QCD (PQCD) picture. In this approach, we calculate…
$B^\pm \to (D^0, \bar D^0, D_{CP})K^{*\pm}_{0,2}$ decays are helpful in determining the CP violation angle $\gamma$, and we analyze these decay processes within the perturbative QCD approach based on $k_T$ factorization. We found that the…
Using the QCD sum rules approach and the complete leading--logarithmic short--distance coefficients determining the penguin--amplitude, we obtain $B(B\to K^*\gamma) = (6.8\pm 2.4)\cdot 10^{-5}$ for top--quark masses in the range (150--200)…
Next-to-leading order QCD corrections to the width difference Delta Gamma in the B_s-meson system are presented. I further discuss how Delta Gamma can be used to detect new physics.
In this work, we give a detailed discussion for QCD factorization involved the complete chirally enhanced power corrections for B decays to two light pseudoscalar mesons, and present some detailed calculations of radiative corrections at…
We study the (tree-level) weak radiative decays of $B$ mesons. We present a numerical estimate for the inclusive $b \to X_c \gamma (\gamma)$ modes based on the free-quark decay. We then review what is known for the $B \to D^\star \gamma$…
In this article, we calculate the $B_c^* \to B_c$ electromagnetic form-factor with the three-point QCD sum rules, then study the radiative decays $ B_c^{*\pm} \to B_c^{\pm} \gamma$. Experimentally, we can study the radiative transitions…
Implications of the recent new measurements of $B\to K_1\gamma$ by Belle are examined. It is shown that the new branching ratio $\calB(B\to K_1(1270)\gamma)$ requires very large form factor compared to the theoretically predicted one. This…
We calculate the next-to-leading corrections to the branching ratio of exclusive $B\to K^* \gamma$ decay. The renormalization scale dependence is reduced compared to the leading logarithmic result but there remains a dependence on a cutoff…
Strengthening constraints on new physics from the B -> X_s gamma branching ratio requires improving accuracy in the measurements and the Standard Model predictions. To match the expected Belle-II accuracy, Next-to-Next-to-Leading Order…
We point out that $R \equiv Br(b\rightarrow d \gamma)/Br(b\rightarrow s \gamma)$ is a sensitive probe of possible violation of CKM unitarity. We compute $R$ in a minimal extension of the Standard Model containing an additional isosinglet…
The B-meson distribution amplitude is calculated using QCD sum rules. In particular we obtain an estimate for the integral relevant to exclusive B-decays \lambda_B = 460 \pm 110 MeV at the scale 1 GeV. A simple QCD-motivated parametrization…
The radiative leptonic $B\to \gamma\ell\nu_{\ell}$ decay serves as an ideal platform to determine the $B$-meson inverse moment which is a fundamental nonperturbative parameter for the $B$ meson. In this paper, we explore precise QCD…
We explored various cases for the branching ratios (BRs) of $B_s\to K^+K^-$, $B_s\to K^0\bar{K}^0$ and $B_d\to \pi^+ \pi^-$ decays. We study the possibility of determining $\gamma $ by using the following the measurements: (a) BRs of…
We predict contributions of higher $K$-resonances to the radiative rare decays $b\to s\gamma$, in the framework of the QCD sum rules on the light cone (LCSR). Our calculations are restricted to the leading twist-two operators for $K^*(892)$…
The radiative decay $ B_{q}^*\to B_{q}\gamma(q=u,d, or s) $ is reexamined with a modified light-cone QCD sum rule method, in which adequate chiral operators are chosen as the interpolating fields in the correlators used for a sum rule…