Related papers: Operator Product Expansion for Exclusive Decays: B…
The experimental information on b --> s l^+ l^- decays has grown enormously during the last couple of years due to BaBar, Belle, CDF and LHCb. Especially, exclusive modes B --> K^(*) l^+ l^-, which have the largest rate and are easily…
We propose a method for a QCD based calculation of one-particle inclusive decays of the form B \to \bar D X or B \to \bar D^* X. It is based on the heavy mass limit and a short distance expansion of the amplitudes, which yield a power…
We use operator product expansion and QCD light-cone sum rules to estimate the amplitude of the decay $B \to J/\psi K $ taking into account leading nonfactorizable contributions. The result is very similar to the estimate obtained earlier…
We present a study of rare decay modes $B^{+} \to D_{s}^{+}h^{0}$, $B^{+} \to D_{s}^{\ast+}h^{0}$, and $B^{+} \to D^{+}h^{0}$, where $h^{0}$ denotes the neutral mesons $\eta$ or $K^{0}$, using a data sample of $(772 \pm 10 ) \times 10^{6}$…
In this paper the decay of $B^+_c$ meson, consisting of two b and c heavy quarks, into the $D^0$ and $K^+$ mesons is studied. Given that the experimental branching ratio for this decay is within the range of $3.72\times 10^{-5}$ to…
Exclusive semileptonic decays of B mesons to orbitally excited D mesons are considered beyond the infinitely heavy quark limit in the framework of the relativistic quark model based on the quasipotential approach. This model agrees with the…
We show how an exceptional point of degeneracy (EPD) is formed in a system composed of an electron beam interacting with an electromagnetic mode guided in a slow wave structure (SWS) with distributed power extraction from the interaction…
In this talk, we consider the computation of D and B fragmentation functions in e+e- annihilation. We present an improved differential cross section that merges together the O(alpha_s^2) fixed-order calculation and the…
While the idea of using the operator product expansion (OPE) to extract the strong coupling from hadronic $\tau$ decay data is not new, there is an ongoing controversy over how to include quark-hadron "duality violations" (i.e., resonance…
A recent lattice QCD study has shown that the $N-J/\psi$ potential is attractive at all distances, and its long-range tail is well described by two-pion exchange. Here, we study to what extent the long-range part of the attraction can be…
We perform an exploratory study of the operator product expansion of the quark propagator on the lattice at short distance in coordinate space. This permits a simple determination of the quark condensate, <qq>^MS(2 GeV)=(-265\pm 5\pm 22…
We show that both the weak phase \beta and the strong phase \delta_d can be determined from the time-dependent measurement of B_d -> D^{*\pm} D^{\mp} decays, whose final states are non-CP eigenstates. It is also possible to extract \beta…
We consider the computation of D and B fragmentation functions in e+e- annihilation. We compare the results of fitting present data using the next-to-leading-logarithmic resummed approach, versus the O(alpha_s^2) fixed-order calculation,…
The weak decays of a spin-$1/2$ doubly charm baryon (${\cal B}_{cc}$) to a spin-$1/2$ singly charm baryon (${\cal B}_c$) and a light vector meson ($V$) are studied under a phenomenological scheme. The contributions are classified into…
The rare $B_c \to D_{s,d}^{*} l^+ l^-$ decays are investigated in the framework of the three point QCD sum rules approach. Considering the gluon condensate corrections to the correlation function, the form factors relevant to these…
For first order systems, we obtain an efficient bound on the exponential decay of an eigenfunction in terms of the distance between the corresponding eigenvalue and the essential spectrum. As an example, the Dirac operator is considered.
The exclusive decay of $\Upsilon$ to a vector plus pseudoscalar charmonium is studied in perturbative QCD. The corresponding branching ratios are predicted to be of order $10^{-6}$ for first three $\Upsilon$ resonances, and we expect these…
The operator product expansion in four-dimensional superconformal field theory is discussed. The OPE takes a particularly simple form for chiral operators, in $N=1$ and $N=2$, and for analytic operators, in $N=2$ and $N=4$. It is argued…
The $B$-meson light-cone distribution amplitude (LCDA) is defined as the matrix element of a quark-antiquark bilocal light-cone operator in the heavy-quark effective theory (HQET) and is a building block of QCD factorization formula for…
The decays \bar{B}-> \bar{K}D and \bar{B}-> \bar{K}\bar{D} taking into account final state interactions are discussed. These decays are described by four strong phases \delta_0,\delta_1,\bar{\delta}_0,\bar{\delta}_1 (subscripts 0 and 1…