Related papers: Perturbative QCD of hard and soft processes
The Odderon state in perturbative QCD is briefly reviewed. Recent calculations devoted to estimate the diffrative eta_c production at high energies from the leading known Odderon states are discussed.
The spectrum of partons in a QCD jet becomes independent of the primary energy in the low momentum limit. This follows within the perturbative QCD from the colour coherence in soft gluon branching. Remarkably, the hadrons follow such…
We apply perturbative QCD to investigate the near threshold heavy quarkonium photoproduction at large momentum transfer. From an explicit calculation, we show that the conventional power counting method will be modified and the three quark…
We propose a simple method to calculate the pion form factor at not very large momentum transfers, which combines the technique of the QCD sum rules with the description of the pion in terms of the set of wave functions of increasing twist.…
We develop a formalism where the hard and soft pomeron contributions to high energy scattering arise as leading Regge poles of a single kernel in holographic QCD. The kernel is obtained using effective field theory inspired by Regge theory…
There are indications of a faith transition in QCD: The strong coupling may freeze at a sufficiently low value to make PQCD relevant even in the confining regime. The properties of PQCD at low Q^2 depend on the asymptotic field…
We comment on the results of a complete leading-twist next-to-leading order QCD analysis of the spacelike pion electromagnetic form factor at large-momentum transfer Q. For the asymptotic distribution amplitude, we have examined the…
We consider the phenomenon of regge cut splitting, corresponding to the BFKL pomeron into an infinite sequence of regge-poles, which happens when one takes into account the running of QCD coupling with scale. The first members of this…
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…
Fragmentation of heavy quarks into heavy-flavoured hadrons receives both perturbative and non-perturbative contributions. We consider perturbative QCD corrections to heavy quark production in $e^+e^-$ collisions to next-to-next-to-leading…
Results presented in perturbative QCD are reviewed. The topics discussed include: - struction functions, - heavy flavour production, - direct photon production, - inclusive production at LHC/SSC, - small $x$ physics, - QCD jets and -…
I discuss the construction of the effective action for QCD suitable for the description of high-energy and small momentum transfer diffractive processes.
We explain how Regge theory and perturbative evolution may be made compatible at small x. The result not only gives striking support to the two-pomeron description of small-x behaviour, but gives a rather clean test of perturbative QCD…
The free energy for QCD at high temperature $T$ is calculated to order $g^5$ using effective-field-theory methods to separate the contributions from the momentum scales $T$ and $gT$. The effects of the scale $T$ enter through the…
We analyse the perturbative contributions from the higher helicity ($\lambda_{1}+\lambda_{1}=\pm 1$) components, which should be naturally contained in the light-cone wave function for the pion as a consequence of the Wigner rotation, in…
A hierarchy of effective field theories is used to separate the contributions from different momentum scales and to calculate the free energy of QCD at high temperature in powers of the coupling constant up to order $g^5$. The behavior of…
With the increasing experimental precision available at colliders, higher-order perturbative calculations are required to reduce the theory uncertainty in order to extract crucial QCD parameters, such as the strong coupling constant, to the…
I survey some recent advances in the applications of the analytical perturbative approach to the description of particle distributions in multi-jet processes. New tests of the perturbatively based picture in the (semi) soft region are…
I discuss hard diffractive scattering in the framework of perturbative QCD and Regge-parametrization.
We develop a new systematic procedure for the Regge limit in perturbative QCD to arbitrary logarithmic order. The formalism relies on the IR structure and the gauge symmetry of the theory. We identify leading regions in loop momentum space…