相关论文: Hard-soft factorization in B_c--> psi pi decay
The B_{s} --> \phi\psi decay is modeled through the inclusive b --> s\psi decay. Using the Vector Meson Dominance model, the amplitude for the chain process B_{s} --> \phi\psi --> \phi\gamma --> \gamma\gamma is estimated and it is found to…
The nonleptonic heavy meson decays $B\to D^{(*)}\pi(\rho), J/\psi K^{(*)}$ and $D\to K^{(*)}\pi$ are studied based on the three-scale perturbative QCD factorization theorem developed recently. In this formalism the Bauer-Stech-Wirbel…
We estimate the decay rates of $\eta_c\rightarrow 2\gamma$, $\eta_c'\rightarrow 2\gamma$, and $J/\psi\rightarrow e^+ e^-$, $\psi^\prime\rightarrow e^+e^-$, by taking into account both relativistic and QCD radiative corrections. The decay…
To describe the weak three-body B decays into pi+ pi- K, we recently derived amplitudes based on two-body QCD factorization followed by pi+ pi- final state interactions in isoscalar S- and isovector P-waves. We study here the sensitivity of…
Armed with the information on the form factor $\fdpi(0)$ inferred from recent CLEO measurements of SU(3)-breaking effects in charmed meson decays, we have studied the form factor $\fbpi$. In the heavy quark limit, $\fbpi(q^2)$ is related to…
We revisit QCD factorization of $B\to \pi\pi$ form factors at large dipion masses, by deriving new constraints based on the analyticity properties of these objects. We then propose a parametrization of the form factors, inspired by the…
In this paper, we studied the quasi-two-body $B_c \to D_{(s)} [ \rho(770),\rho(1450),\rho(1700) \to ] \pi \pi$ decays by employing the perturbative QCD (PQCD) factorization approach. The two-pion distribution amplitudes $\Phi_{\pi\pi}$ are…
The processes of P-wave Quarkonium exclusive decays to two mesons are investigated, in which the final state vector mesons with various polarizations are considered separately. In the calculation, the initial heavy quarkonia are treated in…
We compute the $O(\beta_0 \alpha_s^2)$ QCD corrections to the Standard Model decay $t\rightarrow W^+ b$ as well as the non standard decay $t\rightarrow H^+ b$. We then use our results to compute the BLM scale for these decays, and study the…
We present progress on the calculation of scalar, vector, and tensor form factors for the following meson decays: $B\rightarrow\pi$, $B_s\rightarrow K$, $D\rightarrow\pi$ and $D_s\rightarrow K$. This calculation uses the MILC HISQ gluon…
Motivated by systematic observations of $ B_c $ decays at LHCb, we analyze $B_c^+ \to J/\psi (A, T)$ decays (where $A$ denotes axial-vector mesons $a_1(1260)^+$, $b_1(1235)^+$, and $T$ denotes tensor mesons $a_2(1320)^+$, $K_2^*(1430)^+$)…
A consistent treatment of $B\rightarrow \pi l \nu$ decay is given on the light-front. The $B$ to $\pi$ transition form factors are calculated in the entire physical range of momentum transfer for the first time. The valence-quark…
Motivated by the deviations observed between the data and the SM predictions of $\mathcal{B}(\bar{B}_s^0\to D_s^+ \pi^-)$ and $\mathcal{B}(\bar{B}_d^0\to D^+ K^-)$, we revisit the $B_{c}^{-}\to J/\psi(\eta_{c}) L^{-}$ decays, with $L=\pi,…
A search for the $B^{0}\to K^{+}K^{-}$ decay is performed using $pp$-collision data collected by LHCb. The data set corresponds to integrated luminosities of 1 and 2 fb$^{-1}$ at center-of-mass energies of 7 and 8 TeV, respectively. This…
Cabibbo allowed two-body hadronic weak decays of Lambda b baryons are analyzed in the factorization approximation. We use the covariant oscillator quark model to evaluate the heavy to heavy and heavy to light form factors. When applied in…
The branching fractions of the rare weak $B\to \pi l^+l^-(\nu\bar\nu)$ and $B\to\rho l^+l^-(\nu\bar\nu)$ decays are calculated in the framework of the relativistic quark model based on the quasipotential approach. The form factors…
We present results of the first lattice QCD calculations of the weak matrix elements for the decays $B_c^+ \to D^0 \ell^+ \nu_{\ell}$, $B_c^+ \to D_s^+ \ell^+ \ell^-$ and $B_c^+ \to D_s^+ \nu \overline{\nu}$. Form factors across the entire…
In decay modes $B^0 \to D_s^{(*)+} D_s^{(*)-}$ and $B_s^0 \to D^{(*)+} D^{(*)-}$, none of quarks in final states is the same as one of $B$ meson. They can occur only via annihilation diagrams in the Standard Model. In the heavy quark limit,…
We report results on semileptonic $B\to\pi l\bar{\nu}$ decay form factors near $q^2_{\rm max}$ using NRQCD heavy quark and clover light quark actions and currents improved through $O(\alpha a)$. An inconsistency with the soft pion relation…
Toward the goal of extracting the weak angle alpha, the decay B^0/B^0-bar to a_0^{+/-}pi^{-/+} was recently measured. The decay B^0 to a_0^+pi^- is not only forbidden in the factorization limit of the tree interaction, but also strongly…