Download or read book Identified Hadron Production and Light Quark Fragmentation in Z Decays written by and published by . This book was released on 1998 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have measured the differential cross sections for the production of [pi], K, K°, K*°, [phi], p, [Lambda] and their corresponding antiparticles in separate samples of flavor-tagged Z° 2!light-flavor (u{bar u}, d{bar d}, or s{bar s}), Z° 2!b{bar b} events. Clear flavor dependences are observed, and the results are compared with the predictions of three fragmentation models. We have also performed a direct measurement of A{sub s}, the parity-violating coupling of the Z° to strange quarks, by measuring the left-right-forward-backward production asymmetry in polar angle of the tagged s quark. Our preliminary result is A{sub s} = 0.82 ± 0.10(stat.) ± 0.07(syst.).
Download or read book Identified Hadron Production and Light Quark Fragmentation in Z sup 0 Decays written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We have measured the differential cross sections for the production of[pi][sup+], K[sup+], K[sup 0], K*[sup 0], [phi], p, [Lambda] and their corresponding antiparticles in separate samples of flavor-tagged Z[sup 0][yields] light-flavor (u[bar u], d[bar d], or s[bar s]), Z[sup 0][yields] b[bar b] events. Clear flavor dependences are observed, and the results are compared with the predictions of three fragmentation models. We have also performed a direct measurement of A[sub s], the parity-violating coupling of the Z[sup 0] to strange quarks, by measuring the left-right-forward-backward production asymmetry in polar angle of the tagged s quark. Our preliminary result is A[sub s]= 0.82[+-] 0.10(stat.)[+-] 0.07(syst.).
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 QCD Studies at SLD written by and published by . This book was released on 1997 with total page 14 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{sup *}(892), [phi](1020), p and [Lambda] in hadronic Z° decays and in subsets of flavor-tagged Z° → light-flavor (u{bar u}, d{bar d}, or s{bar s}), Z° → c{bar c} and Z° → b{bar b} events. Charged hadrons were identified with the SLD Cherenkov Ring Imaging Detector. A vertex detector was employed to select flavor-enriched samples, and the polarized electron beam from SLC was used to tag quark and antiquark jets. The authors observes a flavor dependence in the hadron fragmentation functions. They also 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 Production of Charged pi sup Kappa sup and P p in Hadronic Z Decays written by and published by . This book was released on 1999 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have updated our results on identified charged hadron production using the full SLD data sample of 550,000 hadronic Z° decays taken between 1993 and 1998. The SLD Cherenkov Ring Imaging Detector allows the identification of clean samples of charged pions, kaons and protons over a wide momentum range, providing precise tests of perturbative QCD calculations and of fragmentation models. We have studied flavor-inclusive Z° decays, as well as decays into light, c and b flavors, selected using the SLD vertex detector. In addition we have updated our comparison of hadron and antihadron production in light quark (rather than antiquark) jets, selected using the high SLC electron beam polarization. Differences between hadron and antihadron production at high momentum fraction provide precise measurements of leading particle production and new, stringent tests of fragmentation models.
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 Graduel de Lyon written by and published by . This book was released on 1780 with total page 739 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hadron Production in Quark and Antiquark Jets written by and published by . This book was released on 1999 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a number of jet fragmentation measurements ee− --> hadrons. The ALEPH collaboration measures inclusive rho°(770), f0(980) and f2(1270) production rates, improving the world averages. The SLD collaboration measures pi{sup {+-}}, K{sup {+-}} and p/anti-p production in light-, c- and b-flavor Z° decays, as well as leading hadrons in light-quark jets, precisely. The DELPHI collaboration measures the average charged multiplicity in light- and b-flavor events at 183 and 189 GeV, verifying a precise prediction of QCD and excluding flavor-independent fragmentation.
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 1998 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present a preliminary study of correlations in rapidity between pairs of identified pions, kaons and protons in hadronic Z° decays into light flavors. Short range charge correlations are observed between all combinations of these hadron species, confirming that charge, strangeness and baryon number are conserved locally in the jet fragmentation process. The range of this effect is found to be independent of momentum. A strong long-range correlation is observed for high-momentum charged kaon pairs, and weaker long-range [pi]-[pi]−, [pi]-K− and p-K− correlations are observed. 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 signed rapidities and of ordered differences between signed rapidities provide new insights into leading particle production and several new tests of fragmentation models.
Download or read book A Study of Correlations Between Identified Charged Hadrons in Hadronic Z sup 0 Decays written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present a preliminary study of correlations in rapidity between pairs of identified pions, kaons and protons in hadronic Z[sup 0] decays into light flavors. Short range charge correlations are observed between all combinations of these hadron species, confirming that charge, strangeness and baryon number are conserved locally in the jet fragmentation process. The range of this effect is found to be independent of momentum. A strong long-range correlation is observed for high-momentum charged kaon pairs, and weaker long-range[pi][sup+]-[pi][sup -], [pi][sup+]-K[sup -] and p-K[sup -] correlations are observed. 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 signed rapidities and of ordered differences between signed rapidities provide new insights into leading particle production and several new tests of fragmentation models.
Download or read book Measurement of the B Quark Fragmentation Function in Z Decays written by and published by . This book was released on 1999 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present preliminary results of a new measurement of the inclusive b quark fragmentation function in Z° decays using a novel kinematic B hadron energy reconstruction technique. The measurement is performed using 150,000 hadronic Z° events recorded in the SLD experiment at SLAC between 1996 and 1997. The small and stable SLC beam spot and the CCD-based vertex detector are used to reconstruct topological B-decay vertices with high efficiency and purity, and to provide precise measurements of the kinematic quantities used in this technique. We measure the B energy with good efficiency and resolution over the full kinematic range. We compare the measured scaled B hadron energy distribution with several functional forms of the B hadron energy distribution and predictions of several models of b quark fragmentation. Several functions are excluded by the data. The average scaled energy of the weakly decaying B hadron is measured to be x{sub B} = 0.714 " 0.005 (stat) " 0.007 (syst) " 0.002 (model) (preliminary).
Download or read book Light Quark Fragmentation and a Measurement of A sub S at the SLD written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We have studied the fragmentation process in Z[sup 0][yields] light-flavor (u[bar u], d[bar d], s[bar s]) events by measuring the differential cross sections for the production of the identified hadrons[pi][sup[+-]], K[sup[+-]], p/[bar p], K[sub s][sup 0], [Lambda][sup 0]/[bar[Lambda]][sup 0], K*[sup 0]/[bar K]*[sup 0] and[phi], and by performing a preliminary study of correlations in rapidity between pairs of identified[pi][sup[+-]], K[sup[+-]], and p/[bar p]. Short range charge correlations are observed between all combinations of these three hadron species. A strong long range correlation is observed between all combinations of these three hadron species. A strong long range correlation is observed for high-momentum charged kaon pairs, and weaker[pi][sup+][pi][sup -], [pi][sup+]K[sup -] and pK[sup -] correlations are observed. The SLC 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 signed rapidities and of ordered differences between signed rapidities provide new insights into leading particle production and several new tests of fragmentation models. We have used these correlation studies to perform a preliminary direct measurement of the parity violating coupling of the Z[sup 0] to strange quarks, A[sub s]. Our result is: A[sub s]= 0.82[+-] 0.10(stat.)[+-] 0.08(syst.)(preliminary).
Download or read book An Improved Measurement of the B Quark Fragmentation Function in Z Decays at SLD written by and published by . This book was released on 1999 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present preliminary results of a new measurement of the b quark fragmentation function in Z° decays using a novel kinematic B hadron energy reconstruction technique. The measurement is performed using 150,000 hadronic Z° events recorded in the SLD experiment at SLAC between 1996 and 1997. The small and stable SLC beam spot and the CCD-based vertex detector are used to reconstruct topological B-decay vertices with high efficiency and purity, and to provide precise measurements of the kinematic quantities used in this technique. We measure the B energy with good efficiency and resolution over the full kinematic range. We compare the scale B hadron energy distribution with several functional forms of the B hadron energy distribution and predictions of several models of b quark fragmentation. Several functions including JETSET + Peterson are excluded by the data. The average scaled energy of the weakly decaying B hadron is measured to be x{sub B} = 0.719 " 0.005 (stat) " 0.007 (syst) " 0.001 (model) (preliminary).
Download or read book QCD written by and published by . This book was released on 1999 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the B Quark Fragmentation Function in Z0 Decays written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the b-quark inclusive fragmentation function in Z° decays using a novel kinematic B-hadron energy reconstruction technique. The measurement was performed using 350,000 hadronic Z° events recorded in the SLD experiment at SLAC between 1997 and 1998. The small and stable SLC beam spot and the CCD-based vertex detector were used to reconstruct B-decay vertices with high efficiency and purity, and to provide precise measurements of the kinematic quantities used in this technique. We measured the B energy with good efficiency and resolution over the full kinematic range. We compared the scaled B-hadron energy distribution with models of b-quark fragmentation and with several ad hoc functional forms. A number of models and functions are excluded by the data. The average scaled energy of weakly-decaying B hadrons was measured to be x{sub b} = 0.709 " 0.003 (stat) " 0.003 (syst) " 0.002 (model).
Download or read book Production of pi sup K sup K K phi P and Lambda in Hadronic Z Decays written by and published by . This book was released on 1997 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors have measured production rates as a function of momentum of the identified hadrons [pi], K, K°, K*°, [phi], p, [Lambda]° and their antihadrons in inclusive hadronic Z° decays, as well as separately in decays into light, c and b flavors. In addition they have compared hadron and antihadron production rates in light quark (rather than antiquark) jets. The SLD Cherenkov Ring Imaging Detector was used to identify charged hadrons. The vertex detector was used to tag high-purity samples of light- and b-flavor events. The electron beam polarization was used to tag samples of quark and antiquark jets. Clear flavor dependences are observed, consistent with expectations based upon measured production and decay properties of heavy hadrons. They use the light-flavor results to test the predictions of MLLA QCD and of various fragmentation models. Differences between hadron and antihadron production in light quark jets are observed at high momentum fraction, providing direct evidence that higher-momentum particles are more likely to contain a primary quark or antiquark, and they use these results to make a new direct measurement of strangeness suppression in the jet fragmentation process.
