Download or read book Properties of Leading Particles in Hadronic Z Decays written by and published by . This book was released on 1996 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present studies of leading particle production in Z° decays into light, c, and b quarks performed with the SLD experiment at SLAC. The SLD precision vertex detector was exploited to tag light-flavor events, to tag charmed meson vertices and separate the prompt and B-decay components, and to reconstruct B-hadrons partially. The relative production of prompt pseudoscalar and vector D-mesons was measured to be P{sub V} = 0.53 " 0.06(stat.) " 0.02(syst.) (preliminary). The shape of the B-hadron energy spectrum was found to be consistent with the predictions of a number of models, and the average energy fraction was measured to be x{sub E} = 0.697 " 0.012(stat.) " 0.028(syst.) (preliminary). Separation of light quark and antiquark jets was achieved using the highly polarized SLC electron beam, and hadrons were identified using the SLD Cherenkov Ring Imaging Detector. Production of particles and antiparticles in quark jets was compared, allowing the first direct observation of leading particles in ee− --> u{anti u}, d{anti d}, s{anti s} events. More high momentum baryons and K−'s than antibaryons and K's were observed, providing evidence for leading baryon and kaon production, as well as for strangeness suppression at high momentum.
Download or read book Preliminary Measurement of Leading Particle Effects in Hadronic Z sup 0 Decays written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present preliminary evidence for leading particle production in hadronic decays of the Z[sup 0] to light quark pairs using 150,000 events recorded in the SLD experiment at SLAC. The highly polarized electron beam produced by the SLC is used to tag quark and antiquark jets, and a signed impact parameter technique is employed to reject heavy flavor events. Charged hadrons are identified in the SLD Cherenkov Ring Imaging Detector (CRID) and[Lambda]/[bar[Lambda]] are reconstructed using their charged decay modes. In a high purity sample of quark jets, the baryon momentum spectrum is harder that that of the antibaryon, and conversely for a sample of antiquark jets, supporting the hypothesis that the faster particles in jets are more likely to carry the primary quark or antiquark from the Z[sup 0] decay. Similarly, more high momentum K[sup -] that K[sup+] are observed in quark jets and conversely for antiquark jets, consistent with the hypothesis that leading K[sup[+-]] are produced predominantly in s[bar s] events rather than[ital u][bar[ital u]] events.
Download or read book A Study of Correlations Between Identified Charged Hadrons in Hadronic Z Decays written by and published by . This book was released on 1999 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a preliminary study of correlations in rapidity between pairs of identified charged pions, kaons and protons using the entire SLD data sample of 550,000 hadronic Z° decays. Short range charge correlations are observed between all combinations of these hadron species, indicating local conservation of quantum numbers and charge ordering in the jet fragmentation process. The rapidity range of this effect is found to be independent of particle momentum. A strong long-range K-K− correlation is observed at high-momentum and weaker long-range [pi]-[pi]−, [pi]+-K− and p-K− and p{bar p} correlations are observed in light flavor events, providing new information on leading particle production in u, d and s jets. The long-range correlations observed in c{bar c} and b{bar b} events are markedly different and consistent with expectations based on known decay properties of the leading heavy hadrons. In addition, the SLC electron beam polarization is used to tag the quark hemisphere in each event, allowing the first study of rapidities signed such that positive rapidity is along the quark rather than antiquark direction. Distributions of ordered differences in signed rapidity between pairs of particles provide a direct probe of quantum number ordering along the quark-antiquark axis and other new insights into the fragmentation process.
Download or read book Preliminary Measurement of Leading Particle Effects in Hadronic Z Decays written by and published by . This book was released on 1996 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present preliminary evidence for leading particle production in hadronic decays of the Z° to light quark pairs using 150,000 events recorded in the SLD experiment at SLAC. The highly polarized electron beam produced by the SLC is used to tag quark and antiquark jets, and a signed impact parameter technique is employed to reject heavy flavor events. Charged hadrons are identified in the SLD Cherenkov Ring Imaging Detector (CRID) and [Lambda]/{bar {Lambda}} are reconstructed using their charged decay modes. In a high purity sample of quark jets, the baryon momentum spectrum is harder that that of the antibaryon, and conversely for a sample of antiquark jets, supporting the hypothesis that the faster particles in jets are more likely to carry the primary quark or antiquark from the Z° decay. Similarly, more high momentum K− that K are observed in quark jets and conversely for antiquark jets, consistent with the hypothesis that leading K{sup {+-}} are produced predominantly in s{bar s} events rather than {ital u}{bar {ital u}} events.
Download or read book Proceedings Of The 28th International Conference On High Energy Physics In 2 Volumes written by Zygmunt Ajduk and published by World Scientific. This book was released on 1997-04-11 with total page 1878 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 28th conference from the Rochester series was the major high energy physics conference in 1996. Volume one contains short reports on new theoretical and experimental results. Volume two consists of the review talks presented in the plenary sessions.
Download or read book 60 Years Of Cern Experiments And Discoveries written by Herwig Schopper and published by World Scientific. This book was released on 2015-07-13 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is a compilation of the most important experimental results achieved during the past 60 years at CERN - from the mid-1950s to the latest discovery of the Higgs particle. Covering the results from the early accelerators at CERN to those most recent at the LHC, the contents provide an excellent review of the achievements of this outstanding laboratory. Not only presented is the impressive scientific progress achieved during the past six decades, but also demonstrated is the special way in which successful international collaboration exists at CERN.
Download or read book A Study of Correlations Between Identified Charged Hadrons in Hadronic Z0 Decays written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a preliminary study of correlations in rapidity between pairs of identified charged pions, kaons and protons in the SLD data. Details of short-range charge correlations between all combinations of these hadron species are used to study the locality of quantum number conservation, and suggest local charge ordering along the entire hadronization chain. A strong long-range K[sup+]K[sup -] correlation is observed at high-momentum and weaker long-range[pi][sup+]-[pi][sup -], [pi][sup+]-K[sup -] and p-K[sup -] correlations are observed in light flavor events, providing new information on leading particle production in u, d and s jets. The long-range correlations observed in c[bar c] and b[bar b] events are markedly different and consistent with expectations based on known decay properties of the leading heavy hadrons. The SLC electron beam polarization is used to tag the quark hemisphere in each event, allowing the first study of rapidities signed relative to the quark (vs. antiquark) direction. Distributions of ordered, signed rapidity differences provide a new probes of the fragmentation process, including the first direct observation of baryon number ordering along the q[yields][bar q] axis.
Download or read book Hadron Fragmentation Functions and Leading Particle Effects in Hadronic Z Decays written by and published by . This book was released on 1997 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors have measured the differential cross sections for the production of [pi]{sup {+-}}, K{sup {+-}}, K°, K*(892), [phi](1,020), p and [Lambda] in hadronic Z° decays and in subsets of flavor-tagged Z° → light quark (u{anti u}, d{anti d}, or s{anti s}), Z° → c{anti c} and Z° → b{anti b} events. Charged hadrons were identified with the SLD Cherenkov ring imaging detector. The vertex detector was employed to select flavor enriched samples and the polarized electron beam from SLC was used to tag quark and anti-quark jets. The authors observe a flavor dependence in the hadron fragmentation functions. The authors present evidence for leading particle production in hadronic decays of the Z° boson to light-flavor jets and a direct measurement of the strangeness suppression factor [gamma]{sub s}.
Download or read book 97 QCD and High Energy Hadronic Interactions written by J. Thanh Van Tran and published by Atlantica Séguier Frontières. This book was released on 1997 with total page 690 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hadron Fragmentation Functions and Leading Particle Effects in Hadronic Z sup 0 Decays New Results from SLD written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors have measured the differential cross sections for the production of[pi][sup[+-]], K[sup[+-]], K[sup 0], K*(892), [phi](1,020), p and[Lambda] in hadronic Z[sup 0] decays and in subsets of flavor-tagged Z[sup 0][yields] light quark (u[anti u], d[anti d], or s[anti s]), Z[sup 0][yields] c[anti c] and Z[sup 0][yields] b[anti b] events. Charged hadrons were identified with the SLD Cherenkov ring imaging detector. The vertex detector was employed to select flavor enriched samples and the polarized electron beam from SLC was used to tag quark and anti-quark jets. The authors observe a flavor dependence in the hadron fragmentation functions. The authors present evidence for leading particle production in hadronic decays of the Z[sup 0] boson to light-flavor jets and a direct measurement of the strangeness suppression factor[gamma][sub s].
Download or read book Searches for New Particles Produced in Z Boson Decay written by and published by . This book was released on 1990 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Searches for events with new particle topologies in 455 hadronic Z decays with the Mark 2 detector at SLC are presented. 95% confidence level lower limits of 40.7 GeV/c2 for the top quark mass and 42.0 GeV/c2 for the mass of a fourth generation charge - 1/3 quark, regardless of decay mode, are obtained. For a fourth generation sequential Dirac neutrino?4 mass up to 43 GeV/c2. Decays of the Z boson to a pair of non-minimal Higgs bosons (Z → H{sub s}°H{sub p}°), where one of them is relatively light ({approx lt} 10 GeV/c2), are also considered. Limits are obtained on the ZH{sub s}°H{sub p}° coupling as a function of the Higgs boson masses. 11 refs., 2 figs., 2 tabs.
Download or read book Strange Particle Production in Hadronic Z sup 0 Decays written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A study has been made of neutral strange baryons and pseudoscalar mesons produced in hadronic decays of the weak gauge boson V. The experiment was performed at the Stanford Linear Accelerator Center, which has the unique capability of colliding highly polarized electrons with unpolarized positrons. Overall production rates and spectra of the K[sup 0] and the[Lambda][sup 0] (+[Lambda][sup 0]) were measured and compared with other experiments as well as with Quantum Chromodynamics calculations. The combination of the small, stable beam spots produced by the SLAC Linear Collider (SLC) and the precision vertexing capabilities of the SLC Large Detector (SLD) permitted the separation of the hadronic events into three quark flavor-enriched samples. An unfolding was performed to obtain flavor-pure samples, and for the first time measurements were made of K[sup 0] and[Lambda][sup 0] (+[Lambda][sup 0]) production rates and spectra in uds, c, and b quark events at the Z[sup 0] pole. This measurement revealed significant production differences. Utilizing the large quark production asymmetry due to the polarized electron beam, high-purity quark and antiquark jet samples were obtained. The first measurement of production differences of the[Lambda][sup 0] baryon in quark and antiquark jets was performed, which provided clear evidence for a leading particle effect at high momenta.
Download or read book Properties of Hadronic Decays of the Z Boson written by Kathryn F. O'Shaughnessy and published by . This book was released on 1990 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurements of Hadronic Decays of Z Bosons written by and published by . This book was released on 1992 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Z° bosons have been produced by collisions of longitudinally polarized electrons with unpolarized positrons at the SLAC Linear Collider and their decays have been recorded by the SLD experiment. We present preliminary measurements of the properties of the resulting Z° decays into multi-hadronic final states. We find good agreement with the predictions of perturbative QCD and fragmentation models.
Download or read book Particle and Astroparticle Physics written by Alessandro De Angelis and published by Springer Nature. This book was released on 2021-05-27 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents more than 200 problems, with detailed guided solutions, spanning key areas of particle physics and astrophysics. The selected examples enable students to gain a deeper understanding of these fields and also offer valuable support in the preparation for written examinations. The book is an ideal companion to Introduction to Particle and Astroparticle Physics: Multimessenger Astronomy and its Particle Physics Foundations, written by Alessandro De Angelis and Mário Pimenta and published in its second edition in Springer’s Undergraduate Lecture Notes in Physics series in 2018. It can, however, also be used independently. The present book is organized into 11 chapters that match exactly those in the companion textbook, and each of the exercises is given a title to facilitate identification of the subject within that book. Some new exercises have been added because they are considered helpful on the basis of the experience gained by teachers while using the textbook. Beyond students on relevant courses, exercises and solutions in particle and astroparticle physics are of value for physics teachers and to all who seek aid to self-training.
Download or read book A Search for New Particles in Z Decay written by and published by . This book was released on 1989 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have searched 310 hadronic Z decays for evidence of new quarks and leptons. We set lower mass limits of 40.7 GeV/c2 for top, 45 GeV/c2 for bottom prime, and 42.4 GeV/c2 for a heavy neutral lepton assuming their decays are predominantly via the charged current. Limits are also set for other decay modes and for mixtures of decay modes. 10 refs., 10 figs.
Download or read book Measurements of Hadronic Decays of Z sup 0 Bosons written by and published by . This book was released on 1992 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Z[degrees] bosons have been produced by collisions of longitudinally polarized electrons with unpolarized positrons at the SLAC Linear Collider and their decays have been recorded by the SLD experiment. We present preliminary measurements of the properties of the resulting Z[degrees] decays into multi-hadronic final states. We find good agreement with the predictions of perturbative QCD and fragmentation models.
