Download or read book Some Aspects of Quark Fragmentation written by and published by . This book was released on 1984 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The data that the author presents come from the first two years of operation of the High Resolution Spectrometer (HRS) at PEP, and correspond to an integrated luminosity of 106 +- 5 pb−1 (20 pb−1 from the first year and 86 pb−1 from the second year's running). Since the quark-meson transitions may have a particularly simple form at the values of the momentum fraction Z = 2p/sub meson//.sqrt.s, we emphasize this aspect of the data, and show how a sample of e/sup +/e− .-->. (u anti u, d anti d, s anti s) events can be selected. The characteristics of these events are compared to e/sup +/e− .-->. c anti c selected by a D* tag.
Download or read book Quark Fragmentation and Hadron Formation in Nuclear Matter written by Raphaël Dupré and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The hadron formation is, in the framework of the quantum chromodynamics theory (QCD), a non-perturbative process; this characteristic leads to important theoretical challenges. This is why experimental measurements of fragmentation in nuclei are a necessity in order to obtain substantial progress in our understanding of the mechanisms of hadron formation. The thesis begins with the introduction of theoretical background, followed by an overview of theoretical models. The thesis continues with the analysis of Jefferson Lab data obtained with a 5 GeV electron beam incident on various targets (2H, C, Al, Fe, Sn and Pb). The reaction products are measured with the CLAS spectrometer of Hall B. The main results are: (a) a multi-dimensional analysis of the measured observables, which permits a better confrontation with theoretical models and the extraction of temporal information on fragmentation, and (b) the observation of a non linear hadronic attenuation as a function of the target's nuclear radius. The PyQM event generator, developed to reproduce the data from the HERMES collaboration, is also presented. The results are ambivalent, the theoretical basis used does not seem to apply to the studied case, however, some characteristics of the data are reproduced allowing to understand their origin, which is sometimes unexpected. Finally, the possibilities for future experiments, at Jefferson Lab and at an Electron-Ion Collider (EIC), are explored.
Download or read book The Quark Structure of Matter written by Maurice Jacob and published by World Scientific. This book was released on 1992-11-01 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the quark structure of matter has been one of the most important advances in contemporary physics. It has unravelled a new and deeper level of structure in matter, and physics at that level reveals a unity and aesthetic simplicity never before attained. All forces emerge from a unique invariance principle and each of the basic interactions results from a specific symmetry property. Quarks interact among themselves through their ?colour?, as now accurately described by quantum chromodynamics.This volume brings together eight major review articles by Maurice Jacob, a physicist at the forefront of research on the quark structure of matter. He has, in particular, been involved with two research topics in this field. The first is the study of hadronic jets, which one actually sees instead of quarks, because of the opacity of the vacuum to colour. The second is the search for quark matter, a new form of matter believed to exist at high temperatures, when the vacuum should become transparent to colour.The papers in this volume provide a comprehensive review of these phenomenological studies on the quark structure of matter, and also a fasinating insight into the pace of recent progress in these areas. The book comes complete with an original introduction by the author, and also contains a pedagogical review on what is a most engrossing and rewarding field of research in physics.
Download or read book Quark Fragmentation and Trigger Side Momentum Distributions in High P Processes written by G. A. Ringland and published by . This book was released on 1979 with total page 23 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 A Study of Quark Fragmentation Using Kaons Produced in Association with Prompt D s D Mesons written by and published by . This book was released on 2012 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quarks are considered to be the fundamental constituents of hadronic matter, but they have never been observed as free particles. When quarks are produced at high energy colliders, they quickly form bound colorless states, which then decay to produce the particles observed in experiments. The process by which an initially free quark combines with other quarks to form a hadronic particle is called quark fragmentation and has been described using phenomenological models since quarks were first proposed. Since then, several models have been developed to describe the quark fragmentation phenomenon, and these have been tuned to reproduce many average properties of hadrons produced in high energy collisions. In this dissertation, we describe an analysis that probes the properties of particles produced in association with a hadron containing a charm quark that provides a way, for the first time, to study what is thought of as the second particle produced in the process of heavy quar k fragmentation. Data from proton anti-proton collisions was used to carry out this research, which were collected with the CDF II detector at the Fermilab Tevatron and corresponds to 360/pb-1 of integrated luminosity. We reconstruct $D_s^±$ and $D^±$ mesons, which contain charm quarks, and identify the kaons produced in association with them. The kinematic properties of these kaons are compared with predictions of the fragmentation models implemented in the PYTHIA and HERWIG event generators. We find that kaon production in association with $D_s^±$ mesons is enhanced at levels that are in agreement with the fragmentation models but observe differences in production rates of kaons that are produced later in the fragmentation process.
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 Physics written by National Research Council and published by National Academies Press. This book was released on 1999-03-31 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dramatic progress has been made in all branches of physics since the National Research Council's 1986 decadal survey of the field. The Physics in a New Era series explores these advances and looks ahead to future goals. The series includes assessments of the major subfields and reports on several smaller subfields, and preparation has begun on an overview volume on the unity of physics, its relationships to other fields, and its contributions to national needs. Nuclear Physics is the latest volume of the series. The book describes current activity in understanding nuclear structure and symmetries, the behavior of matter at extreme densities, the role of nuclear physics in astrophysics and cosmology, and the instrumentation and facilities used by the field. It makes recommendations on the resources needed for experimental and theoretical advances in the coming decade.
Download or read book Experimental studies on the heavy quark fragmentation functions written by Siegfried Bethke and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Heavy Quark Fragmentation Function at NNLO written by Alexander Mitov and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heavy Quark Fragmentation Functions for D wave Quarkonium and Charmed Beauty Mesons written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quark Fragmentation in E e Annihilation at 29 GeV written by Gregory John Baranko and published by . This book was released on 1983 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lepton and Photon Interactions at High Energies written by Harry W. K. Cheung and published by World Scientific. This book was released on 2004 with total page 575 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains contributions to the XXI International Symposium on Lepton and Photon Interactions at High Energies, held at the Fermi National Accelerator Laboratory. It gives up-to-date reviews of all aspects of particle physics, written by leading practitioners in the field. The review nature of all the articles makes this volume more accessible to students and researchers in other fields of physics. In addition to new experimental data and advances in theory, the future directions and prospects for the field are covered.
Download or read book Heavy Quark Fragmentation Models written by M. A. Gomshi Nobary and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Measurement of B quark Fragmentation Fractions in P p Collisions at centre of Mass Energy written by Wendy Jane Taylor and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fragmentation is the process by which quarks and gluons organize themselves into hadrons. The fragmentation properties of the bottom quark cannot be predicted from fundamental principles and hence must be determined empirically. We investigate one such property, namely the flavour dependence of the fragmentation process for bottom quarks produced in 1.8-TeV proton-antiproton collisions. This flavour dependence is investigated by determining the 'B'-hadron production ratios. We use a sample of pp data corresponding to an integrated luminosity of 110 pb-1 and reconstruct the following semileptonic 'B'-hadron decays into electrons and charmed hadrons: B+[right arrow]e+neD 0X,hsp sp="0.265"B0[right arrow]e+n eD*-X , B0[right arrow]e+neD- X,hsp sp="0.265"B0s[right arrow]e +neD-s X and L0b [right arrow]e+neL- cX . With these data, we measure the ratios of fragmentation fractions fd/fuvmk id="vm1"=88± 21%, fs/fu+fdvmkr rid="vm1"= 21.5±7.1%hsp sp="0.265"and fbaryon/fu+fd vmkr rid="vm1"=12.0±4.2%. Assuming that these four hadrons saturate production of weakly-decaying ' B' hadrons, that is, that fu+fd+fs+fbaryon 1 , we determine fuvmk id="vm1"=39.8±5.4 %, fdvmkr rid="vm1"=35.2±4.8 %, fsvmkr rid="vm1"=16.1±4.5 %hsp sp="0.265"and fbaryonvmkr rid="vm1"=9.0± 2.9%. These results represent the first measurement of all four 'b'-quark fragmentation fractions in a single experiment. These fractions are in agreement both with previous phenomenological interpretations and with other experimental measurements.
Download or read book A Preliminary Measurement of the B Quark Fragmentation Function in Hadronic Z Decays written by and published by . This book was released on 1996 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the {ital b} quark fragmentation function from a sample of semi-leptonic {bold B} decays collected between 1993 and 1995 in the SLD experiment at SLAC. The energy of each tagged {bold B} hadron was reconstructed using information from the lepton and a partially reconstructed charm decay vertex. A comparison of the scaled energy distribution with several phenomenological models of heavy quark fragmentation was made, using the same model in each case to correct the data. The average scaled energy was found to be {l_angle}[chi]{sub E}{r_angle} = 0.697±0.012({ital stat}){sup +0. 028}{sub -0.024} ({ital syst})(preliminary).
