I present a measurement of the W boson mass (M{sub W}) and width ([Gamma]{sub W}) using 200 and 350 pb−1 of CDF Run II data respectively. The measurements, performed in both the electron and muon decay channels, rely on a fit to the W transverse mass distribution. We measure M{sub W} = 80413 ± 48 MeV and [Gamma]W = 2032 ± 71 MeV which represent the world's single most precise measurements to date.
The Tevatron and LEP2 experiments presently provide the most precise direct determinations of the mass and width of the W boson. The combined results are: M[sub w]= 80.394[+-] 0.042 GeV and[Gamma][sub w]= 2.095[+-] 0.106 GeV. The results are in excellent agreement with the predictions of the Standard Model. In this article the latest results are described and the systematic errors which could limit further significant improvements in the precision of these measurements are reviewed.
We discuss the prospects for measuring the W mass and width in Run II. The basic techniques used to measure M{sub W} are described and the statistical, theoretical and detector-related uncertainties are discussed in detail. Alternative methods of measuring the W mass at the Tevatron and the prospects for M{sub W} measurements at other colliders are also described.
The CDF and D0 collaborations have analyzed up to {approx} 200 pb{sup -1} of Run 2 physics data to measure W production properties such as the W cross section, the W width, lepton universality and the W charge asymmetry. From the cross section measurements, CDF obtains a lepton universality of g{sub {mu}}/g{sub e} = 0.998 {+-} 0.012 and g{sub {tau}}/g{sub e} = 0.99 {+-} 0.04 and an indirect W width of {Lambda}{sub W} = 2079 {+-} 41 MeV. D0 measured the W width directly and finds {Lambda}{sub W} = 2011 {+-} 142 MeV. CDF has estimated the uncertainties on the W boson mass measurements in the electron and muon decay channels and obtains an overall uncertainty of 76 MeV.
The two detectors at the Fermilab Tevatron, D0 and CDF, have collected large samples of W and Z decays. With these data measurements of the properties of the W boson have been performed. From the ratio of the W and Z production cross sections a measurement of the W boson width of 2.062 " 0.059 GeV has been obtained. The W boson mass has been measured to be 80.34 " 0.15 GeV. Both detectors have observed diboson production and measured the triple gauge boson couplings. No deviations from Standard Model predictions have been observed.
The 32nd International Conference on High Energy Physics belongs to the Rochester Conference Series, and is the most important international conference in 2004 on high energy physics. The proceedings provide a comprehensive review on the recent developments in experimental and theoretical particle physics. The latest results on Top, Higgs search, CP violation, neutrino mixing, pentaquarks, heavy quark mesons and baryons, search for new particles and new phenomena, String theory, Extra dimension, Black hole and Lattice calculation are discussed extensively. The topics covered include not only those of main interest to the high energy physics community, but also recent research and future plans. Contents: Neutrino Masses and MixingsQuark Matter and Heavy Ion CollisionsParticle Astrophysics and CosmologyElectroweak PhysicsQCD Hard InteractionsQCD Soft InteractionsComputational Quantum Field TheoryCP Violation, Rare Kaon Decay and CKMR&D for Future Accelerator and DetectorHadron Spectroscopy and ExoticsHeavy Quark Mesons and BaryonsBeyond the Standard ModelString Theory Readership: Experimental and theoretical physicists and graduate students in the fields of particle physics, nuclear physics, astrophysics and cosmology.Keywords:High Energy Physics;Particle Physics;Electroweak;QCD;Heavy Quark;Neutrino;Particle Astrophysics;Hadron Spectroscopy;CP Violation;Quark Matter;Future Accelerator
We present a direct measurement of the width of the W boson using the shape of the transverse mass distribution of W → e[nu] candidates selected in 1 fb−1 of data collected with the D0 detector at the Fermilab Tevatron collider in p{bar p} collisions at √s = 1.96 TeV. We use the same methods and data sample that were used for our recently published W boson mass measurement, except for the modeling of the recoil, which is done with a new method based on a recoil library. Our result, 2.028 ± 0.072 GeV, is in agreement with the predictions of the standard model and is the most precise direct measurement result from a single experiment to date.
An overview of W and Z production in high energy hadron collisions is given. W and Z cross section and asymmetry measurements from CDF and D0 are described, with particular emphasis on recent results. The current status of precision W mass and width measurements is reported. The fundamental physics parameters that can be extracted from these measurements are described, and the relevance of W and Z production studies for the LHC is pointed out.
This book is devoted to the broad subject of flavor physics, embracing the question of what distinguishes one type of elementary particles from another. The articles range from the forefront of formal theory (treating the physics of extra dimensions) to details of particle detectors. Although special emphasis is placed on the physics of kaons, charmed and beauty particles, top quarks, and neutrinos, the articles also dealing with electroweak physics, quantum chromodynamics, supersymmetry, and dynamical electroweak symmetry breaking. Violations of fundamental symmetries such as time reversal invariance are discussed in the context of neutral kaons, beauty particles, electric dipole moments, and parity violation in atoms. The physics of the Cabibbo-Kobayashi-Maskawa matrix and of quark masses are described in some detail, both from the standpoint of present and future experimental knowledge and from a more fundamental viewpoint, where physicists are still searching for the correct theory.
