Related papers: Perturbative QCD
I review the status of next-to-leading-order calculations for hadronic final states in deeply-inelastic lepton--nucleon scattering. In more detail, I focus on calculations of (2+1)-jet-type cross sections, describe recent progress in…
We discuss the predictions of perturbative QCD for angular flows of final state particles in two and three jet events including their cms energy and jet resolution (y_{cut}) dependence. The simple analytical formulae for gluon…
Recent progress in application of higher order QCD calculations to jet and inclusive particle production in photon induced collisions is reviewed. Attention is paid to theoretical uncertainties of such calculations, particularly those…
Hard scattering events in high-energy collisions produce highly virtual partons that subsequently fragment into collimated hadronic cascades. When such partonic showers evolve in a QCD medium, as in deep-inelastic scattering or heavy-ion…
The fragmentation function of vector particle into possible bound S-wave states with a heavy antiquark is calculated in the leading order of perturbative QCD for the high energy processes at large transverse momenta with the different…
We discuss our present knowledge of $\alpha_s$, the fundamental running coupling or effective charge of Quantum Chromodynamics (QCD). A precise understanding of the running of $\alpha_s(Q^2) $ at high momentum transfer, $Q$, is necessary…
A short review is given of calculations of the pion electromagnetic and transition form factors within the framework of quantum chromodynamics. It is argued that both the perturbative and nonperturbative aspects of the Q^2 dependence of…
The observation of jets in a variety of hard-scattering processes has allowed the quantitative study of perturbative quantum chromodynamics (PQCD) by comparing detailed theoretical predictions with a wide range of experimental data. This…
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…
Power corrections to hadronic event shapes are estimated using a recently suggested relationship between perturbative and non-perturbative effects in QCD. The infrared cutoff dependence of perturbative calculations is related to…
In these lectures we give a concise introduction to the ideas of renormalon calculus in QED and QCD. We focus in particular on the example of the Adler D function of vacuum polarization, and on relations between perturbative renormalon…
In the cross section for single-inclusive jet production in electron-nucleon collisions, the distribution of a quark in an electron appears at next-to-next-to-leading order. The numerical calculations in Ref. [1] were carried out using a…
A pedagogical introduction to the heavy quark theory is given. It is explained that various expansions in the inverse heavy quark mass $1/m_Q$ present a version of the Wilson operator product expansion in QCD. A systematic approach is…
Hard processes in collider experiments typically produce QCD jets, which have long served as precision tests of QCD in the vacuum. More recently, heavy-ion programs at RHIC and the LHC have offered a novel perspective on jets, establishing…
The interaction of a jet with the medium created in heavy-ion collisions is not yet fully understood from a QCD perspective. This is mainly due to the non-perturbative nature of this interaction which affects both transverse jet momentum…
We discuss various aspects of vector meson production, first analysing the interplay between perturbative and nonperturbative aspects of the QCD calculation. Using a general method adapted to incorporate both perturbative and nonpertubative…
We present a specific class of models for an infrared-finite analytic QCD coupling, such that at large space-like energy scales the coupling differs from the perturbative one by less than any inverse power of the energy scale. This…
Different methods for the calculation of cross sections with many QCD particles are compared. To this end, CSW vertex rules, Berends-Giele recursion and Feynman-diagram based techniques are implemented as well as various methods for the…
Calculations of observables in quantum chromodynamics are typically performed using a method that combines numerical integrations over the momenta of final state particles with analytical integrations over the momenta of virtual particles.…
I illustrate a general formalism based upon the subtraction method for the calculation of next-to-leading order QCD cross sections for any number of jets in any type of hard collisions. I discuss the implementation of this formalism in a…