Download or read book A Study of Hadronization Using Energy Flow from Ee Annihilation Into Quarks and Gluons at square Root s of 29 GeV written by Leslie J. Rosenberg and published by . This book was released on 1985 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Hadronization Using Energy Flow from Ee Annihilation Into Quarks and Gluons at square Root of 29 GeV written by Leslie J. Rosenberg and published by . This book was released on 1985 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Hadronization Using Energy Flow from E e Annihilation Into Quarks and Gluons at square Root s of 29 GeV written by Leslie J. Rosenberg and published by . This book was released on 1985 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Hadronization Using Energy Flow from Ee Annihilation Into Quarks and Gluons At Sqrt S of 29 GeV written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We have made a high statistics study of QCD jets produced in ee− annihilations at .sqrt.s of 29 GeV and observed in the MAC detector located at the PEP storage ring at SLAC. The MAC detector uses calorimetry and provides a homogeneous response over much of its 98% . 4.pi. sr instrumented solid angle. A data sample of well reconstructed hadronic events was selected by requiring that E/sub vis/ in the calorimeters be near .sqrt.s, and almost all the energy be deposited in the central calorimeters. Fits of the jet transverse energy flow are made to the data using String (STR) model and several types of Independent Jet (IJM) model hypotheses, where .alpha./sub s/, the strong coupling constant, and sigma/sub q/, the width of the secondary quark P/sub perpendicular/ distribution, are free parameters. The fits to O(.alpha./sub s/2 using MS-bar renormalization yield .alpha./sub s/ approx.0.17 with the STR hypothesis, and .alpha./sub s/ approx.0.12 with the various IJM hypotheses. The correlations between .alpha./sub s/ and sigma/sub q/ are examined. Detailed comparisons were made with other experimental results. The energy flow projected onto the event plane of 3-jet events selected from the above data sample was studied. The data shows an asymmetric energy flow around the thin jet. Such an asymmetry was predicted by the STR model, and a cluster model (Webber) incorporating soft gluon interference. The various IJM models show no such asymmetry. We associate this asymmetry with coherence effects during hadronization. 106 refs., 58 figs., 18 tabs.
Download or read book A Study of Hadronization Using Energy Flow From e e Annihilation Into Quarks and Gluons at Vs of 29 GeV written by Leslie J. Rosenberg and published by . This book was released on 1985 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Inclusive Hadron Production and Two Particle Correlations in Ee Annihilation at 29 GeV Center of mass Energy written by and published by . This book was released on 1984 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We have studied hadron production in ee− annihilation at 29 GeV center-of-mass energy using the PEP-4 Time Projection Chamber Detector. The inclusive cross sections and mean multiplicities for .pi./sup + -/, K/sup + -/ and (p + anti p) production have been measured using ionization energy loss to separate particle species. We find on average 10.7 +- 0.6 .pi./sup + -/, 1.35 +- 13 K/sup + -/ and 0.60 +- 0.08 (p + anti p) per multihadron event. The differential cross section is well described by a number of Monte Carlo hadronization models. In addition, we have observed correlations in rapidity space for identified pions and kaons. Short-range KK correlations provide evidence for local flavor compensation during hadronization. Long-range .pi pi. and KK correlations indicate that the initial partons carry flavor. We also observe significant long-range .pi. K correlations as a result of heavy quark decays. 85 references, 67 figures, 11 tables.
Download or read book Study of Quark Fragmentation at 29 GeV written by and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of multi-particle final state in high-energy reactions has a long history. Detailed studies of hadronic interactions at Fermilab and at the CERN ISR have shown that particles are emitted in clear jets of hadrons along the beam directions. For the highest energies, a small fraction of events contains large-angle jets originating from hard collisions, in addition to the beam and target fragmentation products. The clearest observation of jets has been in high-energy ee− reactions. Hadronic interactions contain 5 or 6 valence quarks already in the initial state. The final state in ee− annihilation represents at the parton level a relatively simple dynamical system: a q anti q state plus possibly a hard gluon therefore jets produced in e+e− annihilation have to be considered as the cleanest ones. The study of their properties can help, not only to understand quark fragmentation but may also serve as an important tool in the analysis of the much more complex mechanism in hadronic interactions. In this paper we present preliminary results of the overall features of our first sample of e+e− annihilation events at 29 GeV. The data were taken using the High Resolution Spectrometer (HRS) operated at the PEP storage ring at the Stanford Linear Accelerator Center.
Download or read book Study of Quark Fragmentation in Ee Annihilation at 29 GeV written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents the charged particle multiplicity distributions for ee− annihilation at .sqrt.s = 29 GeV measured in the High Resolution Spectrometer. The data, which correspond to an integrated luminosity of 185 pb−1, were obtained at the ee− storage ring PEP. The techniques used to obtain the original distributions from the observed prong numbers are discussed. The multiplicity distribution of the charged particles with a two jet selection has a mean value Nch = 13.02 +- 0.03 +- 0.5; and a dispersion D = 3.84 +- 0.02 +- 0.1. The mean multiplicity increases with the event sphericity. No correlation is observed between the multiplicities in the two jets that characterize most of the events. For the single jets a value of D = 2.71 +- 0.02 +- 0.06 is measured which gives further support the idea of independent jet fragmentation. When compared with e+e− data at other energies, the multiplicity distributions exhibit the scaling behavior in the mean first suggested by Koba, Nielsen and Olsen (KNO). The KNO distribution in the central rapidity interval is broader than that for the whole rapidity span and agrees well with the generalized Bose-Einstein formula for three independent sources. 17 refs., 14 figs.
Download or read book Tests of Models for Parton Fragmentation in E E Annihilation 29 GeV Center of mass Energy written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We examine the distribution of particles in the three jet events of e e annihilation. The data was collected with the PEP-4/Time Projection Chamber detector at 29 GeV center-of-mass energy at PEP. The experimental distributions are compared to the predictions of several fragmentation models which describe the transition of quarks and gluons into hadrons. In particular, our study emphasizes the three fragmentation models which are currently in widest use: the Lund string model, the Webber cluster model and the independent fragmentation model. These three models each possess different Lorentz frame structures for the distribution of hadron sources relative to the overall event c.m. in three jet events. The Lund string and independent fragmentation models are tuned to describe global event properties of our multihadronic annihilation event sample. This tuned Lund string model provides a good description of the distribution of particles between jet axes in three jet events, while the independent fragmentation model does not. We verify that the failure of the independent fragmentation model is not a consequence of parameter tuning or of model variant. The Webber cluster model, which is untuned, does not describe the absolute particle densities between jets but correctly predicts the ratios of those densities, which are less sensitive to the tuning. These results provide evidence that the sources of hadrons are boosted with respect to the overall center-of-mass in three jet events, with components of motion normal to the jet axes. The distribution of particles close to jet axes provides additional support for this conclusion. 94 refs.
Download or read book Hadrons Quarks and Gluons written by J. Thanh Van Tran and published by Atlantica Séguier Frontières. This book was released on 1987 with total page 756 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Total and Inclusive Hadron Production by Ee Annihilation at square Root Symbol S written by James Fraser Patrick and published by . This book was released on 1982 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Total Cross Section and Energy energy Correlations for Electron positron Annihilation Into Hadrons at 29 GeV written by Brian Keith Heltsley and published by . This book was released on 1983 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Properties of Heavy Quark Jets Produced by Ee Annihilation at 29 GeV written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Mark II detector in the ee− storage ring PEP at the Stanford Liner Accelerator Center (SLAC) is used to measure selected properties of hadronic events corresponding to produced bottom or charm quarks. Heavy flavor enrichment is accomplished by tagging events with prompt electrons or muons. Differences between bottom, charm and average jets are observed for momentum, transverse momentum, rapidity and jet mass distributions. A detailed study of the charged multiplicity of b- and c-enriched events finds the mean multiplicity of bottom and charm events to be 16.2 +- 0.5 +- 1.0 and 13.2 +- 0.5 +- 0.9, respectively, where the first error is statistical and the second is systematic. The corresponding 'non-leading' multiplicities of charged particles accompanying the pair of heavy hadrons are 5.2 +- 0.5 +- 0.9 for bottom, and 8.0 +- 0.5 +- 0.9 for charm. We find from these non-leading multiplicities that bottom and charm hadrons fragment with mean energy fractions of z/sub b/ = 0.79/sub -0.05//sup +0.10/ and z/sub c/ = 0.60/sub -0.11//sup +0.09/. These results confirm the expected hard fragmentation of heavy quarks and agree with previous measurements based on leptonic inclusive spectra and D* fragmentation. 48 refs., 29 figs.
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 Hadron Production in Ee Annihilation at 29 GeV written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent results from HRS on the production of scalar, tensor, and charm mesons and of strange and charm baryons in ee− annihilation are presented. The production of f0(975), f2(1270), and K2*(1430) is shown briefly. The decays of D*(2010) and D*(2007)° are studied in detail. The production of .xi.− and .sigma.(1385)/sup + -/ is mentioned. Finally, the preliminary analyses of .lambda./sub c/ and .sigma./sub c//sup 0,++/ productions are presented.
Download or read book Basics of Perturbative QCD written by Yuri Dokshitzer and published by Atlantica Séguier Frontières. This book was released on 1991 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hadron Production in Ee Annihilation QCD and Hadronization written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent results on hadron production in ee− annihilation are summarized. The topics included are: (1) inclusive hadron production, (2) comparison of light (u, d, s) and heavy (c, b) quark jets; (3) p - anti p correlations; (4) gluon vs. quark jets; (5) analysis of 3 jet events; (6) measurement of the strong coupling constant .cap alpha./sub s/; and (7) forward-backward asymmetries of quarks and leptons. Experimental data are compared with predictions of several models to reveal underlying physics. 62 refs., 22 figs.
