Related papers: Heavy Pair Production Currents with General Quantu…
The non-diagonal correlators of vector and scalar currents are considered at three-loop order in QCD. The full mass dependence is computed in the case where one of the quarks is massless and the other one carries mass $M$. We exploit the…
Recent developments in heavy quarknoium physics are reviewed in brief, including (i) nonrelativistic QCD(NRQCD), (ii) the importance of color-octet $(Q\bar{Q})$ components in the decay and the production of a physical heavy quarkonium…
We calculate the anomalous dimensions of higher spin singlet currents in the critical $O(N)$ vector model at order $1/N^2$. The results are shown to be in agreement with the four-loop perturbative computation in $\phi^4$ theory in…
The observation of unpolarized quarkonium production in high energy pp collisions, at mid rapidity, implies a significant violation of the non-relativistic QCD (NRQCD) velocity scaling rules. A precise experimental confirmation of this…
We study the production of heavy quarkonium in association with an additional heavy pair. We argue that important contributions may come from phase space regions where three heavy fermions are separated by relative velocities much lower…
We discuss top-quark pair production at hadron colliders and review available calculations of differential top-pair production cross section in perturbative QCD at approximate next-to-next-to-leading order (NNLO) within the threshold…
Non-relativistic bound state theories for QED and QCD have become fairly mature and amenable to a textbook-level understanding and computation. In this talk we give an introductory review of the following subjects related to the recent…
We present a local subtraction scheme for computing next-to-next-to-leading order QCD corrections to the production of a massive quark-antiquark pair from a colourless initial state. The subtraction terms are built following the…
In two-photon collisions at LEP2 and a future $e^+e^-$ linear collider heavy quarks (mainly charm) will be pair-produced rather copiously. The production via direct and resolved photons can be distinguished experimentally via a remnant-jet…
The threshold scan of top pair production at a future lepton collider allows to determine several Standard Model parameters with very high precision. The recent completion of the third-order QCD corrections to the inclusive top-pair…
In this talk we discuss top-quark pair production in association with an additional jet. We present numerical results based on a next-to-leading order QCD calculation.
There are many outstanding discrepancies comparing the predictions of perturbative QCD and measurements of the rate of production and decay of heavy quark systems. The problems include the $J/\psi \to \rho \pi$ puzzle, leading charmed…
The $O(v^2)$ relativistic correction for inelastic $J/\psi$ photoproduction, in which heavy quark pairs are in the dominant Fock state of the quarkonium, is studied in the framework of NRQCD factorization. An assessment of its significance,…
We calculate the mass and residue of the heavy spin--1/2 baryons containing two heavy b or c quarks in the framework of QCD sum rules. We use the most general form of the interpolating current in its symmetric and anti-symmetric forms with…
The anomalous dimensions of the general flavour non-singlet quark bilinear currents \psi \gamma^{[\mu_1} ... \gamma^{\mu_n]} \psi are computed at three loops in quantum chromodynamics in the minimal subtraction scheme. The dimension of the…
We present the derivation of the NNLO two-parton final state contributions to top pair production in the quark-antiquark channel proportionnal to the leading colour factor $N_c^2$. Together with the three and four-parton NNLO contributions…
We study the effect of the resummation of logarithms for t\bar{t} production near threshold and inclusive electromagnetic decays of heavy quarkonium. This analysis is complete at next-to-next-to-leading order and includes the full…
The associated production of a Higgs boson with a top-antitop quark pair is a crucial process at the LHC since it allows for a direct measurement of the top-quark Yukawa coupling. We present the computation of the radiative corrections to…
The talk is on a computational set-up for calculating the production of a massive quark-antiquark pair in electron positron collisions to order $\alpha_s^2$ in the coupling of quantum chromodynamics (QCD) at the differential level using the…
We calculate the one-loop squared contributions to the next-to-next-to-leading order ${\cal O}(\alpha^2\alpha_s^2)$ radiative QCD corrections for the production of heavy quark pairs in the collisions of unpolarized on--shell photons. In…