Related papers: The C parameter distribution in e+e- annihilation
The emission of energetic gluons in $\tt$ production in $\ee$ annihilation can have important experimental consequences, in particular on top quark mass measurements. We present compact, analytical expressions for the gluon energy…
We show that the B \to X(s) gamma photon energy (E_gamma) spectrum can be reliably computed by resummed perturbation theory. Our calculation is based on Dressed Gluon Exponentiation (DGE) incorporating Sudakov and renormalon resummation. It…
At leading power accuracy the QCD light-cone distribution amplitudes (LCDAs) for a heavy meson can be matched onto the LCDAs in the framework of heavy-quark effective theory (HQET) through a factorization formula. We examine the power…
On the basis of perturbative QCD and the relativistic quark model we calculate relativistic and bound state corrections in the production processes of a pair of P-wave charmonium states. Relativistic factors in the production amplitude…
Using the renormalon calculus, we study the asymptotic behavior of the perturbative expansion of the hard-scattering kernels entering the QCD factorization formula for the nonleptonic weak decays B->D M, where M is a light meson. In the…
We present the first experimental results based on the jet boost algorithm, a technique to select unbiased samples of gluon jets in e+e- annihilations, i.e. gluon jets free of biases introduced by event selection or jet finding criteria.…
We calculate the form factor and cross section of the excited charmonium production process $e^{+}+e^{-}\rightarrow \psi \left ( 2S \right )+\eta _{c}$ by light-cone sum rules. In our method, the form factor depends on the distribution…
Recently, Belle and BaBar Collaborations observed surprising suppression in the endpoint $J/\psi$ spectrum, which stimulates us to examine the endpoint behaviors of the $e^+ e^- \to J/\psi gg$ production. We calculate the $J/\psi$ momentum…
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,…
Experimental tests of QCD predictions for event shape distributions combining contributions from hard and soft processes are discussed. The hard processes are predicted by perturbative QCD calculations. The soft processes cannot be…
Angularities are event shapes whose sensitivity to the splitting angle of a collinear emission is controlled by a continuous parameter $b$, with $ -1 < b < \infty$. When measured with respect to the thrust axis, this class of QCD…
We present predictions for the $e^{+}e^{-}$ event shape angularities at NNLL$^{\prime}$ resummed and $\mathcal{O}(\alpha_s^{2})$ matched accuracy and compare them to LEP data at center-of-mass energies $Q=91.2$ GeV and $Q=197$ GeV. We…
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…
The energy-energy correlation (EEC) in electron-positron annihilation plays a crucial role in precision tests of quantum chromodynamics (QCD) and measurements of the QCD coupling constant. In this paper, we provide a novel analysis for the…
The complete O(alpha) electroweak radiative corrections to e+e- --> WW --> 4f in the electroweak Standard Model are presented in the double-pole approximation. We give analytical and numerical results for the non-factorizable corrections…
We present the results of our recent systematic study of the light-cone expansion of heavy-to-light transition form factors in a model with scalar constituents [1]. We show that the higher-twist contributions (represented in this model by…
We parameterize the enhancement of threshold effects away from hadronic endpoint that arise due to the steeply falling nature of parton distribution functions, within the context of soft-collinear effective theory. This is accomplished in a…
We study the wide angle Compton scattering process on a proton within the soft collinear factorization (SCET) framework. The main purpose of this work is to estimate the effect due to certain power suppressed corrections. We consider all…
Perturbative QCD analysis is presented of the cumulative out-of-plane momentum distribution in the near-to-planar e+e- annihilation events, K_out << Q. In this kinematical region multiple gluon radiation effects become essential. They are…
Using results on soft-collinear factorization for inclusive B-meson decay distributions, a systematic study of the partial B->Xs+gamma decay rate with a cut E_gamma<E_0 on photon energy is performed. For values E_0<1.9 GeV the rate can be…