Related papers: Tests of hard and soft QCD with e+e- Annihilation …
A study of the energy dependence of event shape observables is presented. The strong coupling constant \alpha_s has been determined from the mean values of six event shape observables. Power corrections, employed for the measurement of…
In this thesis I study the infrared limits of QCD beyond leading power by developing effective quantum field theory techniques. I introduce the motivations for studying this subject both as a tool to deepen our understanding of the infrared…
Quantum Chromodynamics (QCD) is a firmly established part of the Standard Model, yet its long distance properties remain challenging at a conceptual level. In recent years significant experimental and theoretical progress has been made…
Within the framework of the effective theory for ultrasoft field modes a problem of interacting an energetic color particle with ultrasoft fluctuations in hot gluon plasma is considered. The procedure of calculation of certain effective…
We review the analysis of polarized structure function data using perturbative QCD at next-to-leading order. We use the most recent experimental data to obtain updated results for polarized parton distributions, first moments and the strong…
The latest results from the H1 and ZEUS collaborations which challenge the QCD description of high energy $ep$ collisions are presented. Data from HERA continue to provide precision measurements and are compared to the latest theoretical…
We analyze the electromagnetic pion and kaon form factor by including radiative and higher-twist effects within the framework of resummed pQCD in the space-like region. We focus on the transition from the perturbative to non-perturbative…
Using data from e+e- annihilation into hadrons, taken with the OPAL detector at LEP at the Z pole between 1991 and 1995, we performed a simultaneous measurement of the colour factors of the underlying gauge group of the strong interaction,…
Modern-day `testing' of (perturbative) QCD is as much about pushing the boundaries of its applicability as about the verification that QCD is the correct theory of hadronic physics. This talk gives a brief discussion of a small selection of…
Recent measurements of selected QCD processes at the Tevatron are reviewed and confronted with theoretical calculations. Results on inclusive jet production at large transverse momentum are compared to predictions from next-to-leading order…
We report on recent studies of QCD performed using reanalysed e+e- annihilation data recorded at centre of mass energies 14<sqrt(s)<44 GeV by the JADE experiment operated 1979 to 1986 at the PETRA e+e- collider at DESY, Hamburg, Germany.…
We elaborate on the relation between perturbative and power-like corrections to short-distance sensitive QCD observables. We confront theoretical expectations with explicit perturbative calculations existing in literature. As is expected,…
QCD predicts soft radiation patterns that are particularly simple for $W+ {jet}$ production. We demonstrate how these patterns can be used to distinguish between the parton-level subprocesses probabilistically on an event-by-event basis. As…
We calculate the probability for rapidity gaps in the parton cascade for different approximations within the perturbative QCD and compare the results with recent measurements. The aim is to find out whether the dual connection between the…
This report summarizes some of the recent HERA results obtained by studying hard processes in ep-scattering. By resolving the structure of the proton, hard ep-reactions provide information on the parton content of the proton and may give…
Some of the most difficult theoretical challenges of QCD occur at the interface of the perturbative and nonperturbative regimes. Exclusive and semi-exclusive processes, the diffractive dissociation of hadrons into jets, and hard diffractive…
Experimental results on hadronic soft and hard diffractive processes are reviewed with emphasis on aspects of the data that point to the underlying QCD mechanism for diffraction. Diffractive differential cross sections are shown to be…
We review the basic concepts of all-order calculations in Quantum Chromodynamics (QCD) and their application to collider phenomenology. We start by discussing the factorization properties of QCD amplitudes and cross-sections in the soft and…
We present complete results for the $O(\alpha_s)$ corrections to the production of a heavy quark pair plus a hard photon, in $e^+ e^-$ annihilation, including both photon and $Z$ intermediate states. Virtual corrections are calculated…
The heavy-quark spectral function in a hot plasma is reconstructed from the corresponding euclidean propagator. The latter is evaluated through a path-integral simulation. A weak-coupling calculation is also performed, allowing to interpret…