Parton fragmentation and string dynamics
TL;DR: In this paper, an iterative cascade-based model for string dynamics is described, which is based on a cascade-fly model using string dynamics, with tunneling in a constant force field.
About: This article is published in Physics Reports.The article was published on 1983-07-01. It has received 2060 citations till now. The article focuses on the topics: Lund string model & Parton.
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University of Genoa1, University of Manchester2, KEK3, CERN4, Imperial College London5, Stanford University6, Tata Institute of Fundamental Research7, Istituto Nazionale di Fisica Nucleare8, University of Pittsburgh9, Lyon College10, TRIUMF11, Northeastern University12, Thomas Jefferson National Accelerator Facility13, University of Córdoba (Spain)14, Goethe University Frankfurt15, University of Southampton16, University of Udine17, University of Alberta18, Tokyo Metropolitan University19, Helsinki Institute of Physics20, National Research Nuclear University MEPhI21, University of Bath22, Niigata University23, Naruto University of Education24, Kobe University25, University of Calabria26, University of Trieste27, European Space Agency28, University of Birmingham29, Ritsumeikan University30, Qinetiq31, École Polytechnique Fédérale de Lausanne32, Massachusetts Institute of Technology33, Brookhaven National Laboratory34
01 Jul 2003-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: The Gelfant 4 toolkit as discussed by the authors is a toolkit for simulating the passage of particles through matter, including a complete range of functionality including tracking, geometry, physics models and hits.
Abstract: G eant 4 is a toolkit for simulating the passage of particles through matter. It includes a complete range of functionality including tracking, geometry, physics models and hits. The physics processes offered cover a comprehensive range, including electromagnetic, hadronic and optical processes, a large set of long-lived particles, materials and elements, over a wide energy range starting, in some cases, from 250 eV and extending in others to the TeV energy range. It has been designed and constructed to expose the physics models utilised, to handle complex geometries, and to enable its easy adaptation for optimal use in different sets of applications. The toolkit is the result of a worldwide collaboration of physicists and software engineers. It has been created exploiting software engineering and object-oriented technology and implemented in the C++ programming language. It has been used in applications in particle physics, nuclear physics, accelerator design, space engineering and medical physics.
18,904 citations
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TL;DR: This biennial Review summarizes much of particle physics, using data from previous editions.
12,798 citations
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6,559 citations
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TL;DR: The Pythia program as mentioned in this paper can be used to generate high-energy-physics ''events'' (i.e. sets of outgoing particles produced in the interactions between two incoming particles).
Abstract: The Pythia program can be used to generate high-energy-physics ''events'', i.e. sets of outgoing particles produced in the interactions between two incoming particles. The objective is to provide as accurate as possible a representation of event properties in a wide range of reactions, within and beyond the Standard Model, with emphasis on those where strong interactions play a role, directly or indirectly, and therefore multihadronic final states are produced. The physics is then not understood well enough to give an exact description; instead the program has to be based on a combination of analytical results and various QCD-based models. This physics input is summarized here, for areas such as hard subprocesses, initial- and final-state parton showers, underlying events and beam remnants, fragmentation and decays, and much more. Furthermore, extensive information is provided on all program elements: subroutines and functions, switches and parameters, and particle and process data. This should allow the user to tailor the generation task to the topics of interest.
6,300 citations
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TL;DR: PYTHIA 8 represents a complete rewrite in C++, and does not yet in every respect replace the old code, but does contain some new physics aspects that should make it an attractive option especially for LHC physics studies.
5,325 citations
References
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TL;DR: In this paper, it was shown that a wide class of non-Abelian gauge theories have, up to calculable logarithmic corrections, free-field-theory asymptotic behavior.
Abstract: It is shown that a wide class of non-Abelian gauge theories have, up to calculable logarithmic corrections, free-field-theory asymptotic behavior. It is suggested that Bjorken scaling may be obtained from strong-interaction dynamics based on non-Abelian gauge symmetry.
3,334 citations
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TL;DR: In this article, the authors show that perturbation theory is arbitrarily good for the deep Euclidean Green's functions of any Yang-Mills theory and of many Yang Mills theories with fermions.
Abstract: An explicit calculation shows perturbation theory to be arbitrarily good for the deep Euclidean Green's functions of any Yang-Mills theory and of many Yang-Mills theories with fermions. Under the hypothesis that spontaneous symmetry breakdown is of dynamical origin, these symmetric Green's functions are the asymptotic forms of the physically significant spontaneously broken solution, whose coupling could be strong.
2,826 citations
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TL;DR: In this paper, the authors compared Dirac's theory of the positron to those proposed by Born and showed that the field strength of large fields differs strongly from those of small fields.
Abstract: [arXiv:physics/0605038]: According to Dirac’s theory of the positron, an electromagnetic field tends to create pairs of particles which leads to a change of Maxwell’s equations in the vacuum. These changes are calculated in the special case that no real electrons or positrons are present and the field varies little over a Compton wavelength. The resulting effective Lagrangian of the field reads: $\cal{L} = \frac{\displaystyle 1}{\displaystyle 2} (\cal{E}^2 - \cal{B}^2) + \frac{\displaystyle e^2}{\displaystyle h c}\int_0^\infty e^{-\eta} \frac{\displaystyle d \eta}{\displaystyle\eta^3}\left\{ i \eta^2 (\cal{EB})\cdot \frac{\displaystyle\cos\left(\frac{\displaystyle\eta}{\displaystyle\vert\cal{E}_k\vert}\sqrt{\cal{E}^2 - \cal{B}^2 + 2i (\cal{EB})}\right) + conj.}{\displaystyle\cos\left(\frac{\displaystyle\eta}{\displaystyle\vert\cal{E}_k\vert}\sqrt{\cal{E}^2 - \cal{B}^2 + 2i (\cal{EB}})\right) - conj. } + \vert\cal{E}\vert^2 + \frac{\displaystyle\eta^2}{\displaystyle 3} (\cal{B}^2 - \cal{E}^2)\right\}$. $\cal{E}$, $\cal{B}$ field strengths. $\vert\cal{E}_k\vert = \frac{\displaystyle m^2 c^3}{\displaystyle e\hbar} = \frac{\displaystyle 1}{\displaystyle 137} \frac{\displaystyle e}{\displaystyle(e^2/m c^2)^2}$ critical field strengths. The expansion terms in small fields (compared to $\cal{E}$) describe light-light scattering. The simplest term is already known from perturbation theory. For large fields, the equations derived here differ strongly from Maxwell’s equations. Our equations will be compared to those proposed by Born. Original German abstract [Z.Phys. 98(1936)714]: Aus der Diracschen Theorie des Positrons folgt, da jedes elektromagnetische Feld zur Paarerzeugung neigt, eine Abanderung der Maxwellschen Gleichungen des Vakuums. Diese Abanderungen werden fur den speziellen Fall berechnet, in dem keine wirklichen Elektronen und Positronen vorhanden sind, und in dem sich das Feld auf Strecken der Compton-Wellenlange nur wenig andert. Es ergibt sich fur das Feld eine Lagrange-Funktion: $\cal{L} = \frac{\displaystyle 1}{\displaystyle 2} (\cal{E}^2 - \cal{B}^2) + \frac{\displaystyle e^2}{\displaystyle h c}\int_0^\infty e^{-\eta} \frac{\displaystyle d \eta}{\displaystyle\eta^3}\left\{ i \eta^2 (\cal{EB})\cdot \frac{\displaystyle\cos\left(\frac{\displaystyle\eta}{\displaystyle\vert\cal{E}_k\vert}\sqrt{\cal{E}^2 - \cal{B}^2 + 2i (\cal{EB}})\right) + konj}{\displaystyle\cos\left(\frac{\displaystyle\eta}{\displaystyle\vert\cal{E}_k\vert}\sqrt{\cal{E}^2 - \cal{B}^2 + 2i (\cal{EB})}\right) - konj } + \vert\cal{E}\vert^2 + \frac{\displaystyle\eta^2}{\displaystyle 3} (\cal{B}^2 - \cal{E}^2)\right\}$. ($\cal{E}$, $\cal{B}$ Kraft auf das Elektron. $\vert\cal{E}_k\vert = \frac{\displaystyle m^2 c^3}{\displaystyle e\hbar} = \frac{\displaystyle 1}{\displaystyle ,,137``} \frac{\displaystyle e}{\displaystyle (e^2/m c^2)^2}$ „Kritische Feldstarke“.) Ihre Entwicklungsglieder fur (gegen $\vert\cal{E}_k\vert$) kleine Felder beschreiben Prozesse der Streuung von Licht an Licht, deren einfachstes bereits aus einer Storungsrechnung bekannt ist. Fur grose Felder sind die hier abgeleiteten Feldgleichungen von den Maxwellschen sehr verschieden. Sie werden mit den von Born vorgeschlagenen verglichen.
2,059 citations
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01 Jan 1972
TL;DR: Feynman as mentioned in this paper proposed the Parton Model and showed that it can be used to explain low-energy photon reactions at extreme energies and the properties of operators in momentum space.
Abstract: * Editors Foreword Richard P. Feynman * 15 General Theoretical Background * 68 Low Energy Photon Reactions * 810 Quark Model of Resonances * 1112 Pseudoscalar Meson Photoproduction, High Energy * 1314 t-Channel Exchange Phenomena * 1421 Vector Mesons and Vector Meson Dominance Hypothesis * 2224 Electromagnetic Form Factors * 2526 Electron-Proton Scattering. Deep Inelastic Region * 2633 Parton Model * 3435 Tests of the Parton Model * 3637 Inelastic Scattering As Properties of Operators * 38 Light Cone Algebra * 3941 Properties of Commutators in Momentum Space * 4247 Electromagnetic Self Energy * 4849 Other Two-Current Effects * 5051 Hypothesis in the Parton Model * 5254 Hadron-Hadron Collisions at Extreme Energies * 55 Final Hadronic States in Deep Inelastic Scattering * 5657 Partons as Quarks
1,394 citations
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TL;DR: In this article, an experimental measure for a precise test of quantum chromodynamics is presented for the asymmetry in the energy-weighted opening angles of the jets of hadrons produced in the process.
Abstract: An experimental measure is presented for a precise test of quantum chromodynamics. This measure involves the asymmetry in the energy-weighted opening angles of the jets of hadrons produced in the process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\mathrm{hadrons}$ at energy $W$. It is special for several reasons: It is reliably calculable in asymptotically free perturbation theory; it has rapidly vanishing (order $\frac{1}{{W}^{2}}$) corrections due to nonperturbative confinement effects; and it is straightforward to determine experimentally.
244 citations