Download or read book Determination of the Strong Coupling Constant sub S and a Test of Perturbative QCD Using W Jets Processes in the D0 Detector written by and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Determination of the Strong Coupling Constant alpha sub S and a Test of Perturbative QCD Using W Jets Processes in the D0 Detector written by and published by . This book was released on 1993 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: The D0 experiment has accumulated data for a study of inclusive W production corresponding to a total integrated luminosity of 14.3 ± 1.7 pb−1 during the 1992--1993 Fermilab Tevatron collider run. The total number of W → e + [nu] candidates is 9770. The ratio of the number of W + 1 jet events to that of W + 0 jet events has been measured as a function of jet minimum E{sub T}. Using this ratio the strong coupling constant, [alpha]{sub s} at Q2 = M{sub W}2 is measured to be [alpha]{sub s}(M{sub W}2) = 0.124 ± 0.005(stat) ± 0.006(MC) ± 0.008(theory){sub -0.022}{sup +0.026}(sys) or ({sub -0.025}{sup +0.028} combined) with a jet minimum E{sub T} of 25 GeV. A quantitative test of perturbative QCD has been made by comparing the experimentally measured ratio with the theoretical predictions. The theoretical predictions of the ratio in both the leading order and next-to-leading order are in good agreement with the measured ratio.
Download or read book Determination of the Strong Coupling Constant alpha s and a Test of Perturbative QCD Using W Jets Processes in the D Detector written by Jaehoon Yu and published by . This book was released on 1993 with total page 238 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 1995 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of the Strong Coupling Constant Using W Jets Processes written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The ratio of the number of W+ 1 jet to W+ 0 jet events is measured with the D0 detector using data from, the 1992--93 Tevatron Collider run. For the W[yields] e[nu] channel with a minimum jet E[sub T] cutoff of 25 GeV, the experimental ratio is 0.065[+-] 0.003(stat)[+-] 0.007(sys). Next-to-Leading order QCD predictions for various parton distributions agree well with each other and are all over one standard deviation below the measurement. Varying the strong coupling constant[alpha][sub s] in both the parton distributions and the partonic cross sections simultaneously does not remove this discrepancy.
Download or read book Test of QCD in Multijet Final States at the Tevatron written by and published by . This book was released on 2011 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this contribution, some of the recent QCD results on jet production from the CDF and D0 experiments in Run II of the Tevatron are discussed. In particular, results include cross section measurements for dijet and trijet production, study of jet substructure and measurements of W/Z+jets cross sections. The measurements are compared with the theoretical predictions. The QCD program at the Tevatron proton-antiproton collider revolves around the jet physics. Jets are collimated sprays of hadrons generated by the fragmentation of partons originating from the hard scattering. The measurements of jets production cross section at the Tevatron provide stringent test of perturbative QCD predictions, information on the strong coupling constant, [alpha]s, and constraints on proton parton distribution functions, PDFs. The deviations from the pQCD predictions could translate into a hint of new physics. In addition, these processes form sizable backgrounds to both, the Standard Model (SM) and beyond SM physics processes. Therefore, good understanding of jets production is essential to perform precise physics measurements or searches for new physics phenomena. In this contribution, a review of some recent QCD results from the CDF [1] and D0 [2] experiments is presented. Various analyses use proton-antiproton collision data from the Fermilab Tevatron at the center of mass energy √s = 1.96 TeV corresponding to integrated luminosities of 0.7 fb−1 to 8 fb−1. The results are corrected for the experimental effects and presented at the 'particle level'. The theory predictions are corrected for the hadronization and underlying effects which are obtained from the parton shower Monte Carlo (MC) simulations.
Download or read book Proceedings Of The 29th International Conference On High Energy Physics Ichep 98 In 2 Volumes written by Alan Astbury and published by World Scientific. This book was released on 1999-06-11 with total page 1899 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings consist of plenary rapporteur talks covering topics of major interest to the high energy physics community and parallel sessions papers which describe recent research results and future plans.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1996 with total page 674 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Tests of Perturbative QCD in W Jets Events Produced in square Root S written by Daniel Patrick Cronin-Hennessy and published by . This book was released on 1997 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1993 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book QCD the DY process written by Andrea L—pez de Recalde and published by Lulu.com. This book was released on 2018-01-03 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent experiments seem to be ready to answer the question whether QCD be the correct theory of strong interactions at all scales, or just an effective high-energy line of a yet undiscovered theory. With the upgraded Large Hadron Collider, a proton-proton collision will reach the Center of Mass (CoM) energy of 14 TeV per colliding pair. Perturbative QCD will then be tested with the highest precision. In this realm, the present book begins reviewing QCD with the aim to focus on the Drell-Yan process and the experiments conceived to validate it. In doing this the approach will be exclusively perturbative. Non perturbative techniques, such as lattice QCD, QCD sum rules, or concepts like the MIT bag model will not be discussed.
Download or read book Determination of the Strong Coupling Constant Up to Complete Second Order in QCD written by Ren-yuan Zhu and published by . This book was released on 1983 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book QCD at D0 and CDF written by and published by . This book was released on 1995 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selected recent Quantum Chromodynamics (QCD) results from the D0 and CDF experiments at the Fermilab Tevatron are presented and discussed. The inclusive jet and inclusive triple differential dijet cross sections are compared to next-to-leading order QCD calculations. The sensitivity of the dijet cross section to parton distribution functions (for hadron momentum fractions (approximately) 0.01 to (approximately) 0.4) will constrain the gluon distribution of the proton. Two analyses of dijet production at large rapidity separation are presented. The first analysis tests the contributions of higher order processes to dijet production and can be considered a test of BFKL or GLAP parton evolution. The second analysis yields a strong rapidity gap signal consistent with colorless exchange between the scattered partons. The prompt photon inclusive cross section is consistent with next-to-leading order QCD only at the highest transverse momenta. The discrepancy at lower momenta may be indicative of higher order processes impacting a transverse momentum or ''k{sub T}'' to the partonic interaction. The first measurement of the strong coupling constant from the Tevatron is also presented. The coupling constant can be determined from the ratio of W + 1jet to W + 0jet cross sections and a next-to-leading order QCD calculation.
Download or read book Physics Briefs written by and published by . This book was released on 1994 with total page 1224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Recent Results on Jet Physics and Tests of QCD Quantum Chromodynamics in E Sup E Sup Minus Annihilation written by and published by . This book was released on 1989 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental investigations to test specific predictions of Quantum Chromodynamics and to adjust the free parameters of the theory are reviewed. Determinations of the strong coupling constant,?{sub s}, in?-decays and in the continuum of ee− annihilations are summarized and discussed. Studies on production rates of multijet hadronic final states in the center of mass energy range of 22 GeV to 93 GeV, including optimizations of both the scale parameter?{sub {ovr MS}} and the renormalization scale?2 in O(?{sub s}2) perturbative QCD, are presented. The status of experimental tests of the nonabelian nature of QCD is summarized. 48 refs., 9 figs., 4 tabs.
Download or read book Multiple Parton Interactions at the LHC written by Paolo Bartalini and published by World Scientific Publishing. This book was released on 2018-11-08 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many high-energy collider experiments (including the current Large Hadron Collider at CERN) involve the collision of hadrons. Hadrons are composite particles consisting of partons (quarks and gluons), and this means that in any hadron–hadron collision there will typically be multiple collisions of the constituents — i.e. multiple parton interactions (MPI). Understanding the nature of the MPI is important in terms of searching for new physics in the products of the scatters, and also in its own right to gain a greater understanding of hadron structure. This book aims at providing a pedagogical introduction and a comprehensive review of different research lines linked by an involvement of MPI phenomena. It is written by pioneers as well as young leading scientists, and reviews both experimental findings and theoretical developments, discussing also the remaining open issues.
Download or read book Experimental Determination of an Effective Coupling Constant written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum chromodynamics (QCD), the theory of the strong force, describes the interactions of two basic building blocks of matter: quarks and gluons. High precision data taken at the Jefferson Lab electron accelerator provide a solid basis for the detailed study of many aspects of QCD. The accelerator's beam energy permits investigations of the transition between the short distance and long distance regimes of the strong force. Understanding how the descriptions of these regimes are related is essential in comprehending the structure of ordinary matter. Using new data from polarized electron - nucleon scattering, we extract the scale dependence of an effective strong coupling constant, $\alpha_{\rm{s}}^{\rm{eff}}$. Our result shows that this effective charge freezes, i.e. loses its scale dependence, at long (nucleon-size) distances. This finite behavior allows us to obtain a physical coupling constant for the strong interaction that is relevant at all scales.
