Related papers: Perturbative QCD below charm threshold: theory and…
We propose a hypothesis on the detailed structure for the representation of the conformal symmetry breaking term in the basic Crewther relation generalized in the perturbation theory framework in QCD renormalized in the ${\rm \bar{MS}}$…
Current experimental information on the charm meson decay observables in which the $c\to s\ell\nu_\ell$ transitions occur is well compatible with the Standard Model predictions. Recent precise lattice calculations of the $D_s$ meson decay…
We review standard applications of perturbative QCD to baryon production, and argue by examining data that it is generally relevant at high but experimentally feasible momentum transfers. Then we consider some new initiatives, particularly…
The calculation of perturbative corrections to the spectral moments observable in hadronic $\tau$ decays is reconsidered. The exact order-$\alpha_s^3$ results and the resummation procedure of Le~Diberder and Pich are compared with a partial…
Rather than sticking to the full $U(3)^3$ approximate symmetry normally invoked in Minimal Flavour Violation, we analyze the consequences on the current flavour data of a suitably broken $U(2)^3$ symmetry acting on the first two generations…
In this paper, we calculate the next-to-next-to-leading-order (NNLO) QCD corrections to $e^+e^- \to J/\psi+\eta_c$ at the $B$ factories. After including the NNLO corrections, the cross section of $e^+e^- \to J/\psi+\eta_c$ is enhanced by…
Electric dipole moment (EDM) of baryons provides a sensitive probe of CP-violating interactions beyond the Standard Model. Motivated by the recent BESIII measurement on the $\Lambda$-hyperon EDM [1], we present the first perturbative QCD…
In the framework of quark-hadron duality, the cross section values of charmonium and doubly charmed baryon production in $e^+e^-$-annihilations have been estimated at interaction energy $\sqrt{s}=10.6$ GeV. It has been shown that the…
Recently it has been shown that the gross structure of the bottomonium spectrum is reproduced reasonably well within the non-relativistic boundstate theory based on perturbative QCD. In that calculation, however, the fine splittings and the…
The bottomonium spectrum up to $n = 3$ is studied within Non-Relativistic Quantum Chromodynamics up to N$^3$LO. We consider finite charm quark mass effects both in the QCD potential and the $\overline{\mathrm{MS}}$-pole mass relation up to…
Measurements performed with pairs of charm mesons produced at threshold from the decay of the $\psi(3770)$ resonance are of great value in flavour physics. The quantum correlation that exists between the two mesons allows unique access to…
We discuss the theoretical underpinnings for the extraordinary success of perturbative QCD in the description of HERA data. In particular, we examine recent progress in the understanding of perturbative QCD at small x. We explain the…
We report on recent progress on five-loop calculations in perturbative QCD. We discuss the computation of the perturbative quark condensate, decoupling in QCD, and the precision determination of charm and bottom quark masses. For the…
We discuss the QCD constraints on e+e- --> baryon-anti-baryon close to threshold, in light of the puzzling experimental data which indicate that close to threshold sigma (e+e- --> n n-bar) > sigma (e+e- --> p p-bar). We focus on the process…
We compute two-loop corrections to the vector current matching coefficient involving two heavy quark masses. The result is applied to the computation of the $\Upsilon(1S)$ decay width into an electron or muon pair. We complement the…
The cross section of the process e^+ e^- -> Z \gamma\gamma -> qq \gamma \gamma is measured with 215 pb^-1 of data collected with the L3 detector during the final LEP run at centre-of-mass energies around 205 GeV and 207 GeV. No deviation…
Conformal symmetry is broken in physical QCD; nevertheless, one can use conformal symmetry as a template, systematically correcting for its nonzero $\beta$ function as well as higher-twist effects. For example, commensurate scale relations…
Recent results on the production of open charm in electron proton scattering at HERA are reviewed. Results on the fragmentation of charm are presented and compared to the measurements at e+e- colliders. Recent results on the charm…
We present a new independent evaluation of the hadronic vacuum polarization contributions a_l{had}(l.o)=(1/2)(g-2)_l{had}(l.o) to the anomalous magnetic moment (anomaly) of the muon and tau leptons using tau-decays and e+e- data. The alone…
We revisit the QCD sum-rule treatment of the isospin-breaking axial correlator in light of the recent claim that a previous treatment produced results incompatible with known chiral constraints. The source of the error in the previous…