Showing papers on "Parton published in 1972"
Book•
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
TL;DR: A review of the theory of Regge cuts, the structure of reggeon coupling functions, and the field-theory approach to the parton model of deep inelastic leptonic processes is given in this article.
108 citations
TL;DR: In this paper, the authors discuss the phenomenological consequences of parton models for photon processes and show that the breakdown of vector-meson dominance in Compton scattering is correlated with its failure in nuclear photoabsorption by showing that the parton model gives rise to a nonshadowed pointlike contribution which occurs only in two-photon processes.
Abstract: We discuss the phenomenological consequences of parton models for photon processes. In particular, the "breakdown" of vector-meson dominance in Compton scattering is correlated with its failure in nuclear photoabsorption by showing that the parton model gives rise to a nonshadowed pointlike contribution which occurs only in two-photon processes. Included in this contribution is a piece which corresponds in the general Compton amplitude ${T}_{\ensuremath{\mu}\ensuremath{
u}}$ to a term which is independent of energy and photon masses at fixed $t$. It is emphasized that failure to observe a contribution with such behavior would have profound consequences for conventional parton models. We predict that this contribution will have only a weak $t$ dependence and will lead to a dominantly real spin-conserving amplitude at large $t$ values for Compton scattering. The ${q}^{2}$ behavior of this fixed pole is most easily detected in wide-angle brems-strahlung experiments, though the same mechanism will also give rise to an $s$-wave enhancement independent of the photon masses in $\mathrm{ee}\ensuremath{\rightarrow}\mathrm{ee}\ensuremath{\pi}\ensuremath{\pi}$.
70 citations
TL;DR: In this article, the contribution of bound state scattering at large energy and angle from the interchange force is calculated, and a new test of the existence of a point-like coupling of the photon to partons is suggested.
61 citations
TL;DR: In this paper, the structure functions of deep inelastic electro-and-neutrino-production on nucleons are derived from the quark parton model or equivalently from a hypothesis of Fritzsch and Gell-Mann on the leading light cone singularity of current commutators.
50 citations
TL;DR: In this article, the scaling property in deep-inelastic electron scattering is established by regarding the physical nucleon as a bound state of a bare nucleon and a bare meson (or a few bare mesons).
Abstract: The scaling property in deep-inelastic electron scattering is established by regarding the physical nucleon as a bound state of a bare nucleon and a bare meson (or a few bare mesons). This bound-state formulation provides a fully relativistic generalization of the "parton" model that is no longer restricted to infinite-momentum frames. It also connects the scaling property in inelastic processes with the rapid decrease of the electromagnetic form factors in elastic scattering. Rigorous statements are derived for specific bound-state solutions of the Bethe-Salpeter equation with the ladder approximation. An Adler sum rule is derived and crossing properties are discussed. A general phenomenological approach is developed which is relativistically covariant and gauge-invariant, and which allows one to correlate directly the observed structure functions and form factors with the appropriate bound-state wave function. If all constituents in the bound state are assumed to be of masses $\ensuremath{\lesssim}1$ GeV, the model gives a qualitative understanding as to why the scaling property is experimentally observed at relatively moderate energies.
41 citations
TL;DR: In this paper, it was shown that present electroproduction experiments cannot distinguish the fractionally charged quark model from certain multitriplet models with integral charges, e.g., the Han-Nambu three-triplet model, which contain additional internal degrees of freedom and predict new "charmed" hadron states which have not yet been observed.
Abstract: It is shown that present inclusive electroproduction experiments cannot distinguish the fractionally charged quark model from certain multitriplet models with integral charges, e.g., the Han-Nambu three-triplet model, which contain additional internal degrees of freedom and predict new "charmed" hadron states which have not yet been observed. Both models are shown to predict identical results if no "charmed" states are produced, and very similar results unless charmed particle production appreciably affects the inclusive cross section.
38 citations
TL;DR: In this article, the authors discuss the phenomena of t / s scaling in proton-proton scattering and analyze the data and show the scaling properties using a parton approach, which leads to similar expressions for the inclusive productions of protons.
31 citations
TL;DR: In this paper, the even charge conjugation part of this reaction is determined by the off-mass shell behaviour of the amplitude γ ∗ + γ − ∗ → hadrons.
30 citations
CERN1
TL;DR: Deep inelastic scattering of longitudinally polarized leptons from polarized nucleons was studied phenomenologically and the parallel antiparallel asymmetry was computed using the quark parton model as discussed by the authors.
28 citations
TL;DR: By transformation of the canonical generators of the Poincare group for a system of N free particles on a spacelike surface, dynamical variables and PoINCare group generators appropriate to the infinite momentum frame, or equivalently on a light like surface, are derived as discussed by the authors.
TL;DR: In this paper, the authors proposed that the asymptotic single-particle distributions f ( x ) = x (d σ /d x ) in inclusive reactions should reflect the limiting longitudinal momentum distribution, ∼ νW 2 ( x ), of the hypothetical partons constituting a hadron.
TL;DR: Gordon and Breach as mentioned in this paper reviewed various aspects of the electromagnetic interactions of hadrons (strongly interacting particles) and illustrated the application of theoretical ideas used in treating both strong and electromagnetic processes, including the parton model of point constituents of the nucleon and the interpretation of the experimental results in terms of the constituent partons.
TL;DR: In this article, it was suggested that the energy spectrum of particles emitted in high energy nucleon-nucleon collisions may scale with increasing energy in a rather simple way, based on the parton model of the nucleon.
Abstract: FEYNMAN1 has recently suggested that the energy spectrum of particles emitted in high energy nucleon-nucleon collisions may “scale” with increasing energy in a rather simple way. The suggestion is based on the parton model of the nucleon and at least some of the predictions seem to fit accelerator and cosmic-ray data2–4.
TL;DR: In this article, the authors make an attempt to grasp some features of hadron physics in terms of light-cone properties, by considering hadrons as aggregates of free massless quarks aligned on the same direction (collinearity).
Abstract: In this paper we make an attempt to grasp some features of hadron physics in terms of light-cone properties. Hadrons are considered, in the light-cone asymptotism, as aggregates of free massless quarks, aligned on the same direction (collinearity). The hadron states are classified by a representation of anO
2.1 algebra, constructed from the generators of the conformal group. Deep inelastic structure functions are evaluated and discussed. Analogies between duality and light-cone physics are stressed.
TL;DR: In this article, it was shown that the hadronic medium is characterized by a tension which is independent of the amount by which it has been stretched, and that the dynamically stable configurations of such a medium are spinning loops, where the tension is balanced against the centrifugal force.
Abstract: Assuming that hadrons are bound states of large numbers of partons and antipartons, we argue that the hadronic medium is characterized by a tension which is independent of the amount by which it has been stretched. The dynamically stable configurations of such a medium are spinning loops, where the tension is balanced against the centrifugal force. The corresponding Regge trajectories are in excellent agreement with experiment, but rise only like ${s}^{\frac{2}{3}}$ for large $s$.
TL;DR: In this paper, two relevant asymptotic limits are pointed out and are shown to be controlled by the two different parton mechanisms, i.e., one of the two final hadrons is forced to emerge predominantly in the direction of the virtual photon in the laboratory.
Abstract: In this paper we study the contrasting dynamical roles played by the "wee" and the "nonwee" partons in the process $\mathrm{ep}\ensuremath{\rightarrow}{e}^{\ensuremath{'}}\mathrm{AB}$ ($A$, $B$ being hadrons) when the negative squared mass ${Q}^{2}$ of the virtual photon becomes large. Two relevant asymptotic limits are pointed out and are shown to be controlled by the two different parton mechanisms which are possible. In each case, one of the two final hadrons is forced to emerge predominantly in the direction of the virtual photon in the laboratory. This imposes testable kinematic restrictions for either limit. Moreover, the behavior of the structure function ${\mathcal{W}}_{2}$ in these two limits is related to the square of the asymptotic electromagnetic form factor times unknown functions of the scaling variables.
TL;DR: Parton model predictions for deep inelastic lepton scattering on nucleons in Weinberg's theory are presented in this paper, where bounds are given for the neutrino and antineutrino cross section and for the neutral cross section.
TL;DR: In this paper, the authors calculate the electromagnetic structure functions from an infinite component wave equation which is a relativistic generalization of the Schrodinger equation of the H atom and show that the result is almost identical to what one would obtain from the parton approximation.
TL;DR: In this paper, the authors considered deep inelastic electron and neutrino scattering for polarized targets, making the analysis from the light-cone quark algebra of Fritzsch and Gell-Mann, and obtained sum rules for the structure functions which contribute to polarization.
Abstract: We consider deep inelastic electron and neutrino scattering for polarized targets. Making the analysis from the light-cone quark algebra of Fritzsch and Gell-Mann, we obtain sum rules for the structure functions which contribute to polarization. We also find that parton model results are contained in the light-cone results. Experimental implications are considered.
TL;DR: In this paper, two parton models are presented for partons having the quantum numbers of the three triplet models proposed by Han and Nambu and by Cabibbo, Maiani and Preparata.
TL;DR: In this paper, light-cone commutators are calculated in the nonperturbative parton model and the results agree with those of Fritzsch and Gell-Mann, and Cornwall and Jackiw.
Abstract: Light-cone commutators are calculated in the nonperturbative parton model The results agree with those of Fritzsch and Gell-Mann, and Cornwall and Jackiw The dynamically dependent terms found by the latter authors are identified and it is argued that they are absent in the softened theory under discussion It is shown how the commutators lead to the same expressions for the deep inelastic structure functions as were obtained in the model previously by direct calculation
TL;DR: In this paper, single-particle electroproduction is discussed in the framework of the covariant parton model and it is found that the discussion of the process is model dependent, but that two contributions are likely to occur.
TL;DR: In this article, it was shown that Bjorken scaling in deep inelastic electron proton scattering implies the validity of the parton model under the technical assumption that the partons are parton models.