Download or read book Test of Quark Fragmentation in the Quark parton Model Framework written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The hadronic system produced in charged-current antineutrino interactions is used to study fragmentation of the d-quark. Some problems encountered in separating the current quark-fragments are discussed. The fragmentation function for the current quark is in good agreement with the expectations of the naive quark-parton model and, in particular, there is no evidence of either a Q2- or x/sub BJ/-dependence. 10 references.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976-03 with total page 938 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Quark parton Fragmentation Functions written by Jean Cleymans and published by . This book was released on 1973 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1988 with total page 1684 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modified Fragmentation Function from Quark Recombination written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Within the framework of the constituent quark model, it isshown that the single hadron fragmentation function of a parton can beexpressed as a convolution of shower diquark or triquark distributionfunction and quark recombination probability, if the interference betweenamplitudes of quark recombination with different momenta is neglected. Therecombination probability is determined by the hadron's wavefunction inthe constituent quark model. The shower diquark or triquark distributionfunctions of a fragmenting jet are defined in terms of overlappingmatrices of constituent quarks and parton field operators. They aresimilar in form to dihadron or trihadron fragmentation functions in termsof parton operator and hadron states. Extending the formalism to thefield theory at finite temperature, we automatically derive contributionsto the effective single hadron fragmentation function from therecombination of shower and thermal constituent quarks. Suchcontributions involve single or diquark distribution functions which inturn can be related to diquark or triquark distribution functions via sumrules. We also derive QCD evolution equations for quark distributionfunctions that in turn determine the evolution of the effective jetfragmentation functions in a thermal medium.
Download or read book Spin 96 Proceedings Of The 12th International Symposium On High energy Spin Physics written by J E J Oberski and published by World Scientific. This book was released on 1997-04-15 with total page 906 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments using highly polarized intense beams and targets, and theoretical studies of spin and polarization phenomena, are now providing us with numerous additional details of the electroweak and strong interactions and the structure of matter. The spin structure of the nucleon has been measured over wide ranges of kinematic variables, and the cross sections have been calculated to several orders in perturbative field theory. At present, the influence of the higher twist contributions, the gluon spin, and the quark orbital angular momentum are under scrutiny. Quantum chromodynamics (QCD) captures a lot of our experimental knowledge of hard polarized scattering processes. Can our understanding of such processes within QCD be further improved?Hyperons produced in high energy reactions show how puzzling strong interactions between hadrons still are. Spin observables in experiments at intermediate energy are used to test parity and charge symmetries. Will they also reveal, at low energy, a violation of time reversal symmetry? We are on the verge of using parity violation measurements at intermediate electron scattering energies to determine the amount of strange quark contributions to the neutral weak form factor of the nucleon. The polarization of the sea quarks is expected to be measured soon in W± decays produced in high energy polarized proton interactions. Will the jets in polarized Z⁰ decays show a definite handedness? These and many other topics are discussed in these proceedings.
Download or read book Government Reports Annual Index written by and published by . This book was released on 1989 with total page 1004 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Introduction to Quarks and Partons written by F. E. Close and published by . This book was released on 1979 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of The 6th International Symposium on Electron and Photon Interactions at High Energies written by H. Rollnik and published by . This book was released on 1974 with total page 579 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of The 6th International Symposium on Electron and Photon Interactions at High Energies Physikalisches Institut University of Bonn Federal Republic of Germany August 27 31 1973 written by Horst Rollnik and published by . This book was released on 1974 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The NJL Model for Quark Fragmentation Functions written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A description of fragmentation functions which satisfy the momentum and isospin sum rules is presented in an effective quark theory. Concentrating on the pion fragmentation function, we first explain the reason why the elementary (lowest order) fragmentation process q → q[pi] is completely inadequate to describe the empirical data, although the "crossed" process [pi] → qq describes the quark distribution functions in the pion reasonably well. Then, taking into account cascade-like processes in a modified jet-model approach, we show that the momentum and isospin sum rules can be satisfied naturally without introducing any ad-hoc parameters. We present numerical results for the Nambu-Jona-Lasinio model in the invariant mass regularization scheme, and compare the results with the empirical parametrizations. We argue that this NJL-jet model provides a very useful framework to calculate the fragmentation functions in an effective chiral quark theory.
Download or read book Heavy Quark Production in Parton Model and in QCD written by and published by . This book was released on 1991 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electromagnetic Interactions of Hadrons written by A. Donnachie and published by Springer. This book was released on 2014-07-08 with total page 586 pages. Available in PDF, EPUB and Kindle. Book excerpt: While electromagnetic interactions were first used to probe the structure of elementary particles more than 20 years ago, their importance has only become fully evident in the last 10 years. In the resonance region, photo production experiments have provided clear evidence for simple quark model ideas, and confirmed the Melosh-transformed SU(6)w as a relevant symmetry classification. At higher energies, their most striking feature is their similarity to hadron-induced reactions, and they have provided fresh insight into the ideas developed to explain strong-interaction physics. New dimensions are added by taking the photon off mass shell, both in the spacelike region, where the development of high-energy electron and muon beams has led to the discovery and study of scaling and the intro duction of "partons," and even more dramatically in the timelike region, where the development of high-energy electron-positron storage rings has led to the exciting discoveries of the last four years. In view of the immense interest stimulated by these developments, an extensive review of our present state of knowledge is both timely and useful. Because of the very wide range of the subject, a cooperative venture presents itself as the most suitable format and is the one we have adopted here. The emphasis throughout is primarily, but not entirely, on phenomenology, concentrating on describing the main features of the experimental data and on the theoretical ideas used directly in their inter pretation.
Download or read book Quark Matter written by Helmut Satz and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the Editors Preface: "Quark Matter 1987 was attended by about 250 scientists, representing 75 research institutions around the world - the scientific community engaged in experimental and theoretical studies of high energy nuclear collisions. The central theme of the meeting was the possibility of achieving extreme energy densities in extended systems of strongly interacting matter - with the ultimate aim of creating in the laboratory a deconfined state of matter, a state in which quarks and gluons attain the active degrees of freedom. High energy accelerator beams and cosmic radiation projectiles provide the experimental tools for this endeavour; on the theoretical side, it is intimately connected to recent developments in the non-perturbative study of quantum chromodynamics. Phase transitions between hadronic matter and quark-gluon plasma are of basic interest also for our understanding of the dynamics of the early universe ... A very special feature of this Sixth Quark Matter Conference was the advent of the first experimental results from dedicated accelerator studies. These were conducted during 1986/87 at the AGS of Brookhaven National Laboratory ... and at the CERN SPS ... An intense discussion of these data formed the main activity of the meeting.
Download or read book Heavy quark production in parton model and in QCD written by and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fragmentation of Quarks and Gluons Tests of QCD in E e Annihilation written by Jonathan Dorfan and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multiple Parton Scattering in Nuclei written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiple scattering, induced radiative energy loss and modified fragmentation functions of a heavy quark in nuclear matter are studied within the framework of generalized factorization in perturbative QCD. Modified heavy quark fragmentation functions and energy loss are derived in detail with illustration of the mass dependencies of the Landau-Pomeranchuk-Migdal interference effects and heavy quark energy loss. Due to the quark mass dependence of the gluon formation time, the nuclear size dependencies of nuclear modification of the heavy quark fragmentation function and heavy quark energy loss are found to change from a linear to a quadratic form when the initial energy and momentum scale are increased relative to the quark mass. The radiative energy loss of the heavy quark is also significantly suppressed due to limited cone of gluon radiation imposed by the mass. Medium modification of the heavy quark fragmentation functions is found to be limited to the large z region due to the form of heavy quark fragmentation functions in vacuum.
