Related papers: QCD Studies at LEP
Several topics from the wide field of QCD studies in Deep-inelastic $ep$ Scattering at HERA are addressed. They include QCD analyses of the inclusive cross section with the determination of $\alpha_s$ and the proton gluon density from the…
Evidence for the production of exotic hadron states composed of five quarks (pentaquarks) has been searched for in data collected by the ALEPH, DELPHI, and L3 experiments at LEP. No significant signal is observed. Several 95% C.L. upper…
Hadronic final states in e+e- annihilitions at centre-of-mass energies from 14GeV up to 189GeV are studied in order to test recent predictions for power corrections to the mean values as well as the distributions of event shape variables.
The confinement transition from the quark and gluon degrees of freedom appropriate in perturbation theory to the hadrons observed by real world experiments is poorly understood. In this strongly interacting transition regime we presently…
An extract of recent results from the H1 and ZEUS Collaborations is shown. Various properties of quantum chromo dynamics are investigated by studying the details of the hadronic final state of high energy electron proton collisions at HERA.…
Recent measurement of inclusive processes and hadronic final states in diffractive deep-inelastic scattering at HERA are used to investigate the QCD factorisation properties and study partonic structure of colour singlet exchange. Resolved…
We present analytic results for first order radiative QCD corrections to e^+e^- annihilation processes into quarks and gluons under the special aspect of polarized final state particles. This aspect involves single-spin polarization, gluon…
Hadronic decays of the $\tau$ lepton provide a clean source to study hadron dynamics in an energy regime dominated by resonances, with the interesting information captured in the spectral functions. Recent results on exclusive channels are…
We compute power corrections to hadronic event shapes in $e^+e^-$ annihilation, assuming an infrared regular behaviour of the effective coupling $\alpha_s$. With the integral of $\alpha_s$ over the infrared region as the only…
We investigate how effectively final-state jet substructure can discriminate between QCD Compton and quark-antiquark annihilation processes from photon-jet production in $pp$ collisions at $\sqrt{s}=13$ TeV. Using infrared- and…
In this note a study of hadronic event shapes in QCD events at the Large Hadron Collider (LHC) is presented. Calorimetric jet momenta, determined by various jet clustering algorithms, are used as input for calculating various event-shape…
After a brief historical review of the emergence of QCD as the quantum field theory of strong interactions, the basic notions of colour and gauge invariance are introduced leading to the QCD Lagrangian. The second lecture is devoted to…
Radiative corrections due to initial state radiation in electron-positron annihilation are calculated within the QED structure function approach. Results are shown in the next-to-leading logarithmic approximation up to $O(\alpha^4 L^3)$…
I review in this presentation some aspects of phenomenology in High Energy Physics which are related to recent and possibly future progress in lattice QCD. In particular, I cover (i) the extraction of CKM matrix elements from B physics,…
New studies of hadronic event shape observables in e+ e- collisions between 13 and 183 GeV CM energy have enabled the running of alpha_s to be confirmed and the validity of non-perturbative power-law corrections to be investigated. A more…
Infrared and collinear events shapes are suited to directly probe properties of hard QCD. They are traditionally used to measure the strong coupling and to test the gauge structure of QCD. Perturbative predictions exist in several…
The study of QCD processes at the LHC will serve two main goals. First, the predictions of Quantum Chromodynamics will be tested and precision measurements will be performed, allowing additional constraints to be established, and providing…
We present a detailed study of photon production in hadronic events in electron-positron annihilation at LEP energies. We show that estimates of the inclusive photon spectrum using the quark-to-photon fragmentation function determined using…
A remarkable number of studies have been performed at LEP in the field of two-photon physics in the last four years. These results represent a very important contribution to the understanding of strong interactions at low energies. In…
The study of light hadrons is central to the understanding of confinement--a unique property of QCD. The quark model describs mesons as bound states of quarks and antiquarks. LQCD and QCD-motivated models for hadrons, however, predict a…