Related papers: Infrared Renormalons and Power Suppressed Effects …
The two-mode coupling model with energy splitting and formation of supermodes with different life times has been pervasive in almost every discipline of physics. We revisit this fundamental model from a different perspective of multipolar…
Deep-inelastic ep scattering data taken with the H1 detector at HERA and corresponding to an integrated luminosity of 106 pb^{-1} are used to study the differential distributions of event shape variables. These include thrust, jet…
We report on several methodologically different NNLO determinations of the strong coupling constant from event shapes and related observables in e+e- annihilation. The event shape distributions are analyzed within a combined framework of…
Benefiting from the high statistics from $e^+e^-$ experiments at the $Z^0$ resonance, it is possible to impose strong two-jet cuts on the data without losing the statistical significance. In these events perturbative activity is suppressed…
Infrared power corrections for Minkowskian QCD observables are analyzed in the framework of renormalon resummation, motivated by analogy with the skeleton expansion in QED and the BLM approach. Performing the ``massive gluon'' renormalon…
We revisit infrared Quantum Electrodynamics (QED) by reformulating the dressing of charged states in terms of a functional Berry connection. In this framework, the electron--photon cloud acquires a topological character, leading to a…
The striking suppression and modification patterns that are observed in jet observables measured in heavy-ion collisions with respect to the proton-proton baseline have the potential to constrain the spatio-temporal branching process of…
We study power corrections to the spin-averaged structure functions F_2 and F_L in the semi-inclusive region. The dramatic breakdown of the operator product expansion at large Bjorken x due to the formation of a narrow jet with invariant…
Several preliminary QCD results from e+e- interactions at LEP are reported. These include studies of event shape variables, which are used to determine alpha_s and for studies of the validity of power corrections. Further, a study of color…
We investigate the nature of power corrections and infrared renormalon singularities in large $\beta_0$ approximation. We argue that the power correction associated with a renormalon pole singularity should appear at O(1), in contrast to…
Jet energy loss and single inclusive jet suppression in high-energy heavy-ion collisions are studied within a pQCD parton model that includes both elastic and radiative interactions between jet shower and medium partons as they propagate…
We compute the next-to-next-to-leading order (NNLO) QCD corrections to the six most important event shape variables related to three-particle final states in electron-positron annihilation. The corrections are sizeable for all variables,…
Within a multiphase transport model, medium modifications of differential jet shapes are investigated in Pb+Pb collisions at $\sqrt{s_{_{\rm NN}}}$ = 2.76 TeV. The differential jet shapes are significantly modified by the strong…
The next-next-to-leading order QCD corrections to the e+e- annihilation into hadrons are considered. The stability of the predictions with respect to change of the renormalization scheme is discussed in detail for the case of five, four and…
The jet shape is a classic jet substructure observable that probes the average transverse energy profile inside a reconstructed jet. The studies of jet shapes in proton-proton collisions have served as precision tests of perturbative…
Non-perturbative corrections to hadronic observables represent a critical obstacle to increasing accuracy at colliders. Long taken to scale simply as $1/Q$, where $Q$ is the centre-of-mass scattering energy, recent work has opened the path…
Studying the substructure of jets has become a powerful tool for event discrimination and for studying QCD. Typically, jet substructure studies rely on Monte Carlo simulation for vetting their usefulness; however, when possible, it is also…
The pion electromagnetic form factor F_{\pi}(Q^{2}) is calculated at the leading order of pQCD using the running coupling constant (\alpha_{S}(Q^{2}(1-x)(1-y))) approach. The resummed expression for F_{\pi}(Q^{2}) is found. It is shown that…
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.
Three-jet event-shape distributions can be exploited to investigate the dependence of hadronisation effects on the colour and the geometry of the underlying hard event. We present here the first comparison of data in e+e- annihilation and…