Related papers: Tests of Quantum Chromo Dynamics at e^+e^- Collide…
QCD is an extensively developed and tested gauge theory, which models the strong interactions in the high-energy regime. In this talk, I shall review the considerable progress which has been achieved in the last few years in the most…
Experimental results on jet physics at LEP and SLC are reviewed and compared with perturbative QCD predictions. The discussion includes determinations of the strong coupling $\as$, measurements of event shape distributions and jet cross…
The goal of the ultra-relativistic heavy ion program is to study Quantum Chromodynamics under finite temperature and density conditions. After a couple of decades of experiment, the focus at the top RHIC and the LHC energy has evolved to…
High energy heavy-ion collisions in laboratory produce a form of matter that can test Quantum Chromodynamics (QCD), the theory of strong interactions, at high temperatures. One of the exciting possibilities is the existence of…
The production of identified hadrons inside jets in $e^+ e^-$ annihilation allows for detailed studies of parton-to-hadron fragmentation functions in a clean environment. We compute hadron-in-jets production cross sections for $e^+e^- \to…
Heavy quarks offer an invaluable hard probe of the droplets of quark gluon plasma (QGP) formed in heavy ion collisions at the LHC and RHIC. Given their large mass, they are predominantly produced in hard scattering processes at the earliest…
Hard probes created through large momentum transfers are used to study the properties of QCD matter created in heavy-ion collisions, by comparing the measurements to those in p+p collisions. Jets, and the "quenching" or suppression of jets…
Quantum Chromodynamics has been studied extensively at Fermilab's Tevatron collider. Between 1992 and 1996 the D{\O}and CDF experiments, each accumulated approximately $100 \mathrm{pb}^{-1}$ of proton-antiproton collisions at a…
The study of quark jets in e+e- reactions at LEP has demonstrated that the hadronisation process is reproduced well by the Lund string model. However, our understanding of gluon fragmentation is less complete. In this study enriched quark…
Data from LEP2 on hadron production in gamma gamma interactions at high pT exceed the predictions of QCD by about an order of magnitude. The amplitude for the process is asymptotically proportional to the sum of the squares of the charges…
Recent studies based on non-perturbative lattice Monte-Carlo solutions of Quantum Chromodynamics, the theory of strong interactions, demonstrated that at high temperature there is a phase change from confined hadronic matter to a deconfined…
I review recent QCD results from LEP. The emphasis is on results that represent new studies and on puzzling disagreements of theory and experiment. Further results are nevertheless mentioned by reference. The new studies discussed in more…
The predicted effects of final state interactions such as colour reconnection are investigated by measuring properties of hadronic decays of W bosons, recorded at a centre-of-mass energy of sqrt(s)=182.7 GeV in the OPAL detector at LEP.…
Quantum Chromodynamics (QCD) is the theory governing the strong interaction of particles. It describes the interactions that bind quarks and gluons into protons and neutrons, and binds these into nuclei. We believe QCD to be as fundamental…
Quantum Chromodynamics is the most successful theory in particle physics. The understanding of all different signals at hadron colliders have been achieved due to the correct interpretation of the theory. In this paper we review some basic…
I describe the current status of tests of perturbative QCD, using measurements of jet, photon, weak boson and heavy flavor production from the Tevatron, LEP and HERA. Measurements of the strong coupling constant are described, and I…
Recently, the ALICE Collaboration reported an enhancement of the yield ratio of strange and multi-strange hadrons to charged pions as a function of multiplicity at mid-rapidity in proton-proton, proton-lead, lead-lead, and xenon-xenon…
Results from the study of jets in hadronic final states produced in e+e- annihilation at sqrt(s)=14 to 209 GeV are discussed. Precise measurements of the strong coupling alpha_S at many points of sqrt(s) provide convincing evidence for the…
We provide a detailed analysis of event-shape observables, namely the energy correlation function and jet angularity, for heavy-flavor jets produced in electron-positron collisions, focusing on quantum chromodynamics (QCD) interactions.…
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…