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Related papers: Tests of hard and soft QCD with e+e- Annihilation …

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In the Standard Model the process e+e- -> gamma-gamma is fully described by QED. Measurements of the differential cross-sections from the four LEP experiments are compared to the QED expectation and limits are set on parameters describing…

High Energy Physics - Experiment · Physics 2017-08-23 K. Sachs

The application of machine learning methods to particle physics often doesn't provide enough understanding of the underlying physics. An interpretable model which provides a way to improve our knowledge of the mechanism governing a physical…

Computational Physics · Physics 2023-07-19 Marko Jercic , Nikola Poljak

We study the moments of hadronic event shapes in $e^+e^-$ annihilation within the context of next-to-next-to-leading order (NNLO) perturbative QCD predictions combined with non-perturbative power corrections in the dispersive model. This…

High Energy Physics - Phenomenology · Physics 2014-11-20 T. Gehrmann , M. Jaquier , G. Luisoni

QED processes at electron-positron colliders are considerd. We present differential cross-sections for large-angle Bhabha scattering, annihilation into muons and photons. Radiative corrections in the first order are taken into account…

High Energy Physics - Phenomenology · Physics 2009-10-30 A. B. Arbuzov , G. V. Fedotovich , E. A. Kuraev , N. P. Merenkov , V. D. Rushai , L. Trentadue

It is unusual to find QCD factorization explained in the language of quantum information science. However, we will discuss how the issue of factorization and its breaking in high-energy QCD processes relates to phenomena like decoherence…

Quantum Physics · Physics 2021-08-30 C. A. Aidala , T. C. Rogers

We introduce a method for the separation of soft and collinear logarithms in QCD parton evolution at $\mathcal{O}(\alpha_s^2)$ and at leading color. Using an implementation of the technique in the Dire parton shower, we analyze the…

High Energy Physics - Phenomenology · Physics 2022-06-29 Leif Gellersen , Stefan Höche , Stefan Prestel

This is a short review of some hard two-photon processes: $\\ a) \,\,\gamma\gamma\to {\overline P}_1 P_2,\,\, {\overline P}_1 P_2= \{\pi^+\pi^-, K^+ K^-, K_S K_S, \pi^o\pi^o, \pi^o\eta\}\,, \\ b) \,\,\gamma\gamma\to V_1 V_2,\,\, V_1…

High Energy Physics - Phenomenology · Physics 2015-06-22 Victor L. Chernyak , Simon I. Eidelman

Hard processes in high-energy proton-nucleus collisions are a powerful tool in order to investigate several importants aspects of QCD in a nuclear medium, such as nuclear shadowing, parton multiple scattering or medium-induced gluon…

High Energy Physics - Phenomenology · Physics 2016-12-26 François Arleo

This lecture note presents a self-contained introduction to the theory of a heavy quark-antiquark ($Q\bar{Q}$) system in terms of perturbative QCD. The lecture is intended for non-experts, such as graduate course students. The heavy…

High Energy Physics - Phenomenology · Physics 2014-12-01 Y. Sumino

This talk reports on work aimed at improving our understanding of charged states in gauge theories.Emphasis is placed on different ways of implementingthe gauge invariance of physical states. QED perturbative calculations are used to stress…

High Energy Physics - Phenomenology · Physics 2007-05-23 E. Bagan , M. Lavelle , D. McMullan , B. Fiol , N. Roy

With an eye toward LHC processes in which theoretical precisions of 1 percent are desired, we introduce the theory of the simultaneous YFS resummation of QED and QCD to compute the size of the expected resummed soft radiative threshold…

High Energy Physics - Phenomenology · Physics 2011-07-19 B. F. L. Ward , C. Glosser , S. Jadach , S. A. Yost

Hard QCD processes in ultrarelativistic heavy-ion collisions become increasingly relevant and they can be used as probes of the dense matter formed during the violent scatterings. We will discuss how one can use these hard probes to study…

Nuclear Theory · Physics 2009-10-30 Xin-Nian Wang

I review recent results in QCD at high energy, emphasizing the role of higher-order computations, power corrections, and Monte Carlo simulations in the study of a few discrepancies between data and perturbative predictions, and discussing…

High Energy Physics - Phenomenology · Physics 2015-06-25 S. Frixione

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…

High Energy Physics - Experiment · Physics 2007-05-23 W. J. Metzger

We present first calculations of QCD matrix-elements in perturbation theory at finite Nc beyond 2 loops in the eikonal approximation for e+ e- annihilation processes. For the emission of n soft energy-ordered gluons we solve both the colour…

High Energy Physics - Phenomenology · Physics 2015-07-07 Kamel Khelifa-Kerfa , Yazid Delenda

We seek a model which describes both the high-energy soft $pp$ data and has the perturbative QCD attributes expected in the low x, relatively low Q^2 domain. We describe the present status of this endeavour.

High Energy Physics - Phenomenology · Physics 2011-07-26 A. D. Martin , M. G. Ryskin , V. A. Khoze

I discuss the calculation of QCD jet rates in e+e- annihilation as a testing ground for parton shower simulations and jet finding algorithms.

High Energy Physics - Phenomenology · Physics 2017-08-23 Bryan R. Webber

We provide a brief review of the current status of resummed predictions for QCD final state observables such as event shapes and jet rates in a variety of different hard processes. Particular emphasis is given to more recent developments…

High Energy Physics - Phenomenology · Physics 2009-11-10 Mrinal Dasgupta

I describe the recent success in performing accurate calculations of the effects of the strong force on particles containing bottom and charm quarks. Since quarks are never seen in isolation, and so cannot be studied directly, numerical…

High Energy Physics - Lattice · Physics 2009-11-11 Christine Davies

We review the extension of the factorization formalism of perturbative QCD to soft rescattering associated with hard processes in nuclei.

High Energy Physics - Phenomenology · Physics 2014-11-17 Jianwei Qiu , George Sterman