Download or read book Measurements of Z Electroweak Couplings at SLD written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present a summary of the results of several electroweak measurements performed by the SLD experiment at the Stanford Linear Collider (SLC). Most of these results are preliminary and are based, unless otherwise indicated, on the full 1993--8 data set of approximately 550,000 hadronic decays of Z° bosons produced with an average electron beam polarization of 73%.
Download or read book Z Quark Coupling Measurements at SLD written by and published by . This book was released on 2000 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The SLD experiment at SLAC has performed several precise tests of the electroweak Standard Model. This paper summarizes the measurements of Z couplings to quarks. Most of these measurements are preliminary and many incorporate the full SLD dataset of 550,000 polarized Z decays.
Download or read book Measurements of Z to Heavy quark Couplings at SLD written by and published by . This book was released on 1999 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present measurements of Z° to heavy-quark coupling electroweak parameters, R{sub b}, R{sub c}, and parity-violation parameter A{sub c}, from SLD. The measurements are based on approximately 550k hadronic Z° events collected in 1993-98. Obtained preliminary results of R{sub b} and R{sub c} measurements are R{sub b} = 0.2159 " 0.0014 " 0.0014 and R{sub c} = 0.1685 " 0.0047 " 0.0043. In the A{sub c} measurement, we use four methods to determine the initial-quark charge: combined Kaon charge and Vertex charge, lepton, exclusively reconstructed D*, D-mesons, and a new method using inclusive soft-pion from D*. The preliminary results of these four methods were combined to give A{sub c} = 0.634 " 0.027.
Download or read book Precision Electroweak Measurements on the Z Resonance written by Delphi Aleph (L3, Opal, SLD, Collaboration) and published by . This book was released on 2005 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. the data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLD experiment using a polarized beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarized asymmetries. The mass and width of the Z boson, m{sub Z} and {Lambda}{sub Z}, and its couplings to fermions, for example the {rho} parameter and the effective electroweak mixing angle for leptons, are precisely measured: m{sub Z} = 91.1875 {+-} 0.0021 GeV; {Lambda}{sub Z} = 2.4952 {+-} 0.0023 GeV; {rho}{sub {ell}} = 1.0050 {+-} 0.0010; sin{sup 2} {theta}{sub eff}{sup lept} = 0.23153 {+-} 0.00016. The number of light neutrino species is determined to be 2.9840 {+-} 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model. At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its Standard Model expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m{sub t} = 173{sub -10}{sup +13} GeV, and the mass of the W boson, m{sub W} = 80.363 {+-} 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the Standard Model. Using in addition the direct measurements of m{sub t} and m{sub W}, the mass of the as yet unobserved Standard Model Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level.
Download or read book Beheira written by and published by . This book was released on 1953 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 96 Electroweak Interactions and Unified Theories written by J. Thanh Van Tran and published by Atlantica Séguier Frontières. This book was released on 1996 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electroweak Coupling Measurements from Polarized Bhabha Scattering at the Z Resonance written by and published by . This book was released on 1994 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cross section for Bhabha scattering (ee− → e+e−) with polarized electrons at the center of mass energy of the Z° resonance has been measured with the SLD experiment at the SLAC Linear Collider (SLC) during the 1992 and 1993 runs. The first measurement of the left-right asymmetry in Bhabha scattering (A{sub LR}e+e− ) is presented. From A{sub LR}{sup e+}e− the effective weak mixing angle is measured to be sin2?{sub W}{sup eff} = 0.2245 ± 0.0049 ± 0.0010. The effective electron vector and axial vector couplings to the Z° are extracted from a combined analysis of the polarized Bhabha scattering data and the left-right asymmetry (A{sub LR}) previously published by this collaboration. From the combined 1992 and 1993 data the effective electron couplings are measured to be v{sub e} = -0.0414 ± 0.0020 and a{sub e} = -0.4977 ± 0.0045.
Download or read book Operator s Manual written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Final Results on Electroweak Asymmetries from SLD written by and published by . This book was released on 2000 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: I present the final measurements of the Z boson-lepton coupling asymmetry parameters A{sub e}, A{sub {mu}}, and A{sub {tau}}, obtained from the complete sample of polarized Z bosons collected by the SLD detector at the SLAC Linear Collider. The measurements use leptonic Z decays and the results are A{sub e} = 0.1544 ± 0.0060, A{sub {mu}} = 0.142 ± 0.015, and A{sub {tau}} = 0.136 ± 0.015. The A{sub e} result is combined with the left-right asymmetry using Z decays to hadrons, A{sub LR}° (''' A{sub e}), and is found to be A{sub e} = 0.1516 ± 0.0021. Assuming lepton universality, a combined effective weak mixing angle of sin2 [theta]{sub W}{sup eff} = 0.23098 ± 0.00026 is obtained. Using additional Standard-Model parameters an upper limit on the Higgs mass is given.
Download or read book Electroweak Coupling Measurements from Polarized Bhabha Scattering at SLD written by and published by . This book was released on 1994 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cross section for Bhabah scattering (ee− → e+e−) with polarized electrons at the center of mass energy of the Z° resonance has been measured with the SLD experiment at the SLAC Linear Collider (SLC) during the 1992--1993 runs. The first measurement of the left-right asymmetry in Bhabah scattering (A{sub LR}{sup e+}e− ) is presented. From A{sub LR}{sup e+}− the effective weak mixing angle is measured to be sin2?{sub W}{sup eff} = 0.2245±0.0010. When combined with the measurement of A{sub LR}, the effective electron couplings are measured to be v{sub e} = -0.0414±0.0020 and a{sub e} = -0.4977±0.0045.
Download or read book Electroweak Coupling Measurements from Polarized Bhabha Scattering at the Z sup 0 Resonance written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The cross section for Bhabha scattering (e[sup +]e[sup [minus]] [yields] e[sup +]e[sup [minus]]) with polarized electrons at the center of mass energy of the Z[sup 0] resonance has been measured with the SLD experiment at the SLAC Linear Collider (SLC) during the 1992 and 1993 runs. The first measurement of the left-right asymmetry in Bhabha scattering (A[sub LR]e[sup +]e[sup [minus]] ([theta])) is presented. From A[sub LR][sup e+]e[sup [minus]]([theta]) the effective weak mixing angle is measured to be sin[sup 2][theta][sub W][sup eff] = 0.2245 [+-] 0.0049 [+-] 0.0010. The effective electron vector and axial vector couplings to the Z[sup 0] are extracted from a combined analysis of the polarized Bhabha scattering data and the left-right asymmetry (A[sub LR]) previously published by this collaboration. From the combined 1992 and 1993 data the effective electron couplings are measured to be v[sub e] = [minus]0.0414 [+-] 0.0020 and a[sub e] = [minus]0.4977 [+-] 0.0045.
Download or read book A Combination of Preliminary Electroweak Measurements and Constraints on the Standard Model written by and published by . This book was released on 2004 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: This note presents a combination of published and preliminary electroweak results from the four LEP collaborations and the SLD collaboration which were prepared for the 2003 summer conferences. Averages from Z resonance results are derived for hadronic and leptonic cross sections, the leptonic forward-backward asymmetries, the [tau] polarization asymmetries, the b{bar b} and c{bar c} partial widths and forward-backward asymmetries and the q{bar q} charge asymmetry. Above the Z resonance, averages are derived for di-fermion cross sections and forward-backward asymmetries, photon-pair, W-pair, Z-pair, single-W and single-Z cross sections, electroweak gauge boson couplings, W mass and width and W decay branching ratios. Also, an investigation of the interference of photon and Z-boson exchange is presented, and colour reconnection and Bose-Einstein correlation analyses in W-pair production are combined. The main changes with respect to the experimental results presented in summer 2002 are updates to the mass of the W boson, four-fermion cross sections and gauge couplings, all measured at LEP-2, and the LEP heavy-flavour results measured at the Z pole. The results are compared with precise electroweak measurements from other experiments, notably the recent final result on the electroweak mixing angle determined in neutrino-nucleon scattering by the NuTeV collaboration and the new result in atomic parity violation in Caesium. The parameters of the Standard Model are evaluated, first using the combined LEP electroweak measurements, and then using the full set of electroweak results.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 994 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electroweak Interactions and Unified Theories written by and published by . This book was released on 1996 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Collective Motion And Phase Transitions In Nuclear Systems Proceedings Of The Predeal International Summer School In Nuclear Physics written by Virgil Baran and published by World Scientific. This book was released on 2007-04-05 with total page 690 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the invited contributions that were presented at the Predeal International Summer School in Nuclear Physics 2006. It covers the recent achievements in the fields of nuclear structure, double beta decay, nuclear multifragmentation, kaon and dilepton production in heavy ion collisions, and the quark-gluon plasma. The treatment is both theoretical and experimental, with emphasis on the collective aspects and related phase transitions. The papers are authored by many leading researchers in the field.
Download or read book Physics in Collision 14 written by Stephen Keller and published by Atlantica Séguier Frontières. This book was released on 1995 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt:
