相关论文: b \to ss\bar{d}$ in a Vector Quark Model

In this paper, we calculate the branching ratios for B^0\to D_s^+\pi^-, B^+\to D_s^+\pi^0, B^0\to D_s^{*+}\pi^- and B^+\to D_s^{*+}\pi^0 decays in the perturbative QCD factorization approach. We find that the calculated branching ratios of…

We analyze the decay $D_s\to \phi \pi$ with QCD factorization in the heavy quark limit. The nonfactorizable contributions, including hard spectator contribution are discussed and numerical results are presented. Our predictions on the…

Within the framework of perturbative QCD approach, we study the charmless two-body decays into final states involving one axial-vector (A), $a_1(1260)$ or $b_1(1235)$, and one vector (V), namely $\rho(\omega,\phi)$. Using the decays…

I describe the theoretical progress in the study of semileptonic tree-level B decays, and its interplay with recent experimental results. In particular, I focus on two anomalies: the ratios $R(D^{(*)})=\displaystyle\frac{{\cal B}(B \to…

The ${\Upsilon}(1S)$ ${\to}$ $B_{c}D_{s}^{\ast}$ weak decay is studied with the perturbative QCD approach firstly. It is found that (1) main contributions to branching ratio come from the longitudinal and parallel helicity amplitudes, (2)…

The implications of the latest measurement of the branching fraction of B($ b\rightarrow s \gamma $) of b hadrons, which is another signature of New Physics beyond Standard Model is presented here. The quark transitions $ b \rightarrow s $,…

The nonleptonic two-body $B^{\ast}$ ${\to}$ $\bar{D}D$ weak decays are studied phenomenologically with the perturbative QCD factorization approach. It is found that the $B_{s}^{{\ast}0}$ ${\to}$ $D_{s}^{-}D_{s}^{+}$, $B_{d}^{{\ast}0}$…

The decay constant for the vector state of $3S$-level in the heavy $(\bar b c)$-quarkonium is evaluated in the framework of sum rules for the mesonic currents. A scaling relation for the constants of vector quarkonia with different quark…

The quasi-two-body $B \to D (R\to) K \pi$ decays are calculated in PQCD approach based on the $k_T$ factorization by introducing the wave functions of $K\pi$ pair associated with the resonances $K^*(892)$, $K_0^*(1430)$ and $K_2^*(1430)$.…

Motivated by the observation of the decay B to K* gamma by the CLEO collaboration, we have systematically analyzed the weak radiative decay Lambda_b to Lambda gamma, evaluating the confined effects of quarks in the covariant oscillator…

We carry out a detailed study of exclusive radiative rare $B$-decays in the framework of the QCD sum rules on the light cone, which combines the traditional QCD sum rule technique with the description of final state vector mesons in terms…

We study the exclusive leptonic and semileptonic $B$ decays $B \to \ell^- \bar\nu$ and $B \to D^{(\ast)} \ell^-\bar\nu$ in the framework of the covariant quark model with built-in infrared confinement. We compute the relevant form factors…

Exclusive $B_c^\ast \rightarrow D_{s}~\nu \bar{\nu}$ decay is studied in the framework of the three--point QCD sum rules approach. The two gluon condensate contributions to the correlation function are calculated and the form factors of…

We describe a light-cone QCD sum rule calculation of the $B_s\to f_0(980)$ transition form factors useful to predict the branching ratios of the rare decays $B_s \to f_0 \ell^+ \ell^-$, $B_s \to f_0 \nu \bar \nu$ and of $B_s\to J/\psi f_0$…

Inspired by the recent LHCb measurements and forthcoming great potential on $B_{c}$ meson, we study the exclusive $B_{c}$ ${\to}$ $B_{q}P$, $B_{q}V$ decays with the perturbative QCD approach, where $q$ $=$ $u$, $d$, $s$; $P$ and $V$ denote…

The form factors of weak decays of $B_s$ mesons to ground state $D_s^{(*)}$ mesons as well as to their radial $D_s^{(*)}(2S)$ and orbital $D_{sJ}^{(*)}$ excitations are calculated in the framework of the relativistic quark model based on…

We consider the effects of a non-vanishing strange-quark mass in the determination of the full basis of dimension six matrix elements for $B_{s}$ mixing, in particular we get for the ratio of the $V-A$ Bag parameter in the $B_s$ and $B_d$…

B meson rare decays ($B\to K(K^{*})l\bar l$ and $B\to K^*\gamma$) are analyzed in the framework of effective field theory of heavy quarks. The semileptonic and penguin type form factors for these decays are calculated by using the light…

In this paper, we calculate the top quark rare decay t-ch in a supersymmetric extension of the standard model where baryon and lepton numbers are local gauge symmetries. Adopting reasonable assumptions on the parameter space, we find that…

The inclusive decay rate b to ccs is enhanced considerably due to perturbative QCD corrections. We recalculate the dominant part of the NLO-QCD corrections, because they cannot be reconstructed from the literature and we give the full…