相关论文: Radiative $B \to K^* \gamma $ transition in QCD

In this paper, the strong form factors and coupling constants of $D_sDK^*$ and $D_sD^*K^*$ vertices are investigated within the three-point QCD sum rules method with and without the $SU_{f}(3)$ symmetry. In this calculation, the…

We use QCD sum rules to estimate the leading-order universal form factors describing the semileptonic B decay into orbital excited $D$-wave charmed doublets, including the ($1^{-}$, $2^{-}$) states ($D_{1}^{*}$, $D'_{2}$) and the ($2^{-}$,…

We study the decay modes of B_{s}^{0}(\bar{B}_{s}^{0})-->D_{s}^{\pm} K^{\mp}, B_{s}^{0}(\bar{B}_{s}^{0})-->D^{\pm} \pi^{\mp} and B^{0}(\bar{B}^{0})-->D^{\pm} \pi^{\mp} in the perterbative QCD approach based on k_T factorization, including…

We study the radiative charmless $B_{(s)}\to V(A)\gamma $ decays in perturbative QCD (pQCD) approach to the leading order in $\alpha_s$ (here $V$ and $A$ denotes vector mesons and two kinds of axial-vector mesons: $^3P_1$ and $^1P_1$…

Radiative $\bar{B}^0(\bar{B}^0_s)\rightarrow J/\psi \gamma$ decays provide an interesting case to test our understanding of (non)perturbative QCD and eventually to probe physics beyond the standard model. Recently, the LHCb Collaboration…

Exclusive semileptonic B decays to radially excited charmed mesons and rare radiative B decay to the orbitally excited tensor K_2^*(1430) meson are investigated in the framework of the relativistic quark model based on the quasipotential…

The decay rates for the exclusive B decays $B \rightarrow K \eta_c $ and $B \rightarrow K^* \eta_c$ are calculated in the context of the heavy quark effective theory. We obtain $\Gamma (B \rightarrow K \eta_c )/\Gamma (B\rightarrow K\psi…

The decays $K_{L,S} \to 3 \gamma $ are not forbidden by any selection rules or symmetry principles. However, gauge invariance and Bose statistics dictate that every photon pair in these transitions has at least two units of angular…

The rare B decays Bs(d)-->\mu\mu, B-->K*\mu\mu and Bs-->\phi\gamma are studied using up to \sim 0.41 fb^{-1} of pp collisions at \sqrt{s} = 7 TeV collected by the \lhcb experiment in 2010 and 2011. A search for the decays Bs(d)-->\mu\mu, is…

Combining our results for various O(alpha_s^2) corrections to the weak radiative B-meson decay, we are able to present the first estimate of the branching ratio at the next-to-next-to-leading order in QCD. We find BR(B -> X_s gamma) = (3.15…

Recently, the LHCb Collaboration performed first search for the rare radiative $\Xi_{b}^{-}\rightarrow \Xi^{-}\gamma$ decay and put an upper limit, ${\cal B}(\Xi_{b}^{-}\to \Xi^{-}\gamma) < 1.3 \times 10^{-4}$, on its branching ratio. The…

We study the decays of $B_{s,d} \to l^+ l^- \gamma (l=e, \mu,\tau)$ within the light-front model. We calculate the tensor type form factors and use these form factors to evaluate the decay branching ratios. We find that, in the standard…

We present upgraded theoretical predictions for inclusive and exclusive radiative decays of {\it B} mesons. Our results include those next-to-leading order corrections that have already been computed. Our best estimates in the Standard…

The form factors relevant to $B_{q}\to D^{\ast}_{q}(J^{P}=1^{-})\ell\nu$ $(q=s, d, u)$ decays are calculated in the framework of the three point QCD sum rules approach. The heavy quark effective theory prediction of the form factors are…

We present results of the first lattice QCD calculations of $B_c \to B_s$ and $B_c \to B_d$ weak matrix elements. Form factors across the entire physical $q^2$ range are then extracted and extrapolated to the physical-continuum limit before…

Efforts to predict the rare exclusive decay $B\to K^{\ast}\gamma$ from the well known inclusive decay $b\to s\gamma$ are frustrated by the effect of the large recoil momentum. We show how to reduce the large uncertainty in calculating this…

We study the $f^+$ form factor for the $\bar B_s\to K^+\ell^-\bar\nu_\ell$ semileptonic decay in a nonrelativistic quark model. The valence quark contribution is supplemented with a $\bar B^*$-pole term that dominates the high $q^2$ region.…

We compute the form factors parametrizing radiative leptonic decays of heavy mesons B^+\to\gamma e^+\nu for photon energies much larger than \Lambda_{QCD}, where perturbative QCD methods for exclusive processes can be combined with the…

The strong coupling constants of spin-3/2 to spin-1/2 doubly heavy baryon transitions with light vector mesons are estimated within the light-cone QCD sum rules method. Moreover, using the vector-meson dominance ans\"atz, the widths of…

We compare the Standard Model (SM) predictions for the differential branching ratio of the rare $B\to K^*\nu\bar\nu$ decays using $B \to K^*$ form factors obtained from holographic light-front QCD (hLFQCD) and Sum Rules (SR) Distribution…