Download or read book A Measurement of the Left hand Forward backward Asymmetry for Charm Quarks Using Dsup and Dsup Mesons written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Polarized Forward backward Asymmetry of Z B bar B Using a Lifetime Tag and Momentum weighted Track Charge written by and published by . This book was released on 1995 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a direct measurement of the parity-violating parameter A{sub b} by analyzing the left-right forward-backward asymmetry of b quarks in ee− --> Z{sup o} --> b{bar b}. The SLD experiment observes hadronic decays of Z{sup o} bosons produced at resonance in collisions of longitudinally polarized electrons and unpolarized positrons at the SLC. Heavy flavor decays of the Z{sup o} are identified by taking advantage of the long lifetime of B hadrons, the small, stable SLC beam spot, and precise tracking from SLD. The asymmetry A{sub b} is measured with a self-calibrating technique employing momentum-weighted track charge from both hemispheres in the tagged events. From our 1994--1995 sample of 3.6 pb−1 of ee− annihilation data with a luminosity-weighted average e− polarization of 77.3%, and our 1993 sample of 1.8 pb−1 with a luminosity-weighted polarization of 63.1%, we obtain A{sub b}(preliminary) = 0.843 " 0.046(stat.) " 0.051(syst.).

Download or read book Energy Research Abstracts written by and published by . This book was released on 1986 with total page 936 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Polarized Forward backward Asymmetry of Quarks Using Momentum weighted Track Charge at SLD written by Thomas Robert Junk and published by . This book was released on 1995 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Inclusive Forward Backward textbf textrm t bar textrm textbf t Production Asymmetry and Its Rapidity Dependence textrm textbf dA textrm textbf fb written by and published by . This book was released on 2010 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Early measurements of a large forward-background asymmetry at the CDF and D0 experiments at Fermilab have generated much recent interest, but were hampered by large uncertainties. We present here a new measurement of the parton level forward-backward asymmetry of pair-produced top quarks, using a high-statistics sample with much improved precision. We study the rapidity, y{sub top}, of the top quark production angle with respect to the incoming parton momentum in both the lab and t{bar t} rest frames. We find the parton-level forward-backward asymmetries to be A{sub fb}{sup p{bar p}} = 0.150 ± 0.050{sup stat} ± 0.024{sup syst} A{sub fb}{sup t{bar t}} = 0.158 ± 0.072{sup stat} ± 0.024{sup syst}. These results should be compared with the small p{bar p} frame charge asymmetry expected in QCD at NLO, A{sub fb} = 0.050 ± 0.015. Additionally, we introduce a measurement of the A{sub fb} rapidity dependence dA{sub fb}/d([Delta]y). We find this to be A{sub fb}{sup t{bar t}}).

Download or read book Measurement of the Forward backward Charge Asymmetry in Electron positron Annihilation Into a Quark antiquark Pair written by David Donald Stuart and published by . This book was released on 1992 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Polarized Forward backward Asymmetry of beta Quarks Using Momentum weighted Track Charge at SLD written by Thomas Robert Junk and published by . This book was released on 1995 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Preliminary Direct Measurement of the Parity Violating Coupling of the Z to Strange Quarks A sub S written by and published by . This book was released on 1999 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present an updated direct measurement of the parity-violating coupling of the Z° to strange quarks, A{sub s}, derived from the full SLD data sample of approximately 550,000 hadronic decays of Z° bosons produced with a polarized electron beam and recorded by the SLD experiment at SLAC between 1993 and 1998. Z° → s{bar s} events are tagged by the presence in each event hemisphere of a high-momentum K{sup ±}, K{sub s} or [Lambda]°/{bar {Lambda}}° identified using the Cherenkov Ring Imaging Detector and/or a mass tag. The CCD vertex detector is used to suppress the background from heavy-flavor events. The strangeness of the tagged particle is used to sign the event thrust axis in the direction of the initial s quark. The coupling A{sub s} is obtained directly from a measurement of the left-right-forward-backward production asymmetry in polar angle of the tagged s quark. The background from u{bar u} and d{bar d} events is measured from the data, as is the analyzing power of the method for s{bar s} events. We measure: A{sub s} = 0.85 ± 0.06(stat.) {+-} 0.07(syst.)(preliminary).

Download or read book Corrections to Quark Asymmetries at LEP written by and published by . This book was released on 2004 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most precise measurement of the weak mixing angle sin2 [theta]{sub eff}{sup l} at LEP is from the forward-backward asymmetry ee− 2!b{bar b} at the Z-pole. In this note the QED and electroweak radiative corrections to obtain the pole asymmetry from the measured asymmetry for b- and c-quarks have been calculated using ZFITTER, which has been amended to allow a consistent treatment of partial two-loop corrections for the b-quark final asymmetries. A total correction of [delta]A{sub FB}{sup b} = 0.0019 ± 0.0002 and [delta]A{sub FB}{sup c} = 0.0064 ± 0.0001 has been found, where the remaining theoretical uncertainty is much too small to explain the apparent discrepancy between sin2 [theta]{sub eff}{sup l} obtained from A{sub FB}{sup b} and from the left-right asymmetry at SLD.

Download or read book Measurement of the Polarized Forward backward Asymmetry of B Quarks Using Momentum weighted Track Charge at SLD written by and published by . This book was released on 1995 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a direct measurement of the parity-violating parameter A{sub b} by analyzing the polarized forward-backward asymmetry of b quarks in ee− --> Z° --> b{bar b}. Data were taken at the Stanford Linear Accelerator Center (SLAC), with the Stanford Large Detector (SLD), which records the products of ee− interactions at a center of mass energy (square root)s = 91.2 GeV/c2 at the SLAC Linear Collider (SLC). The SLC/SLD experimental apparatus provides a unique and ideal environment for measuring electroweak asymmetries. Heavy flavor decays of the Z° were identified inclusively by taking advantage of the long lifetime of B hadrons, the small, stable SLC beam spot, and SLD's precise tracking detectors. Two analysis techniques for measuring A{sub b} are presented: a binned fit to the left-right forward-backwards asymmetry of tagged events signed with momentum-weighted track charge, and a self-calibrating maximum-likelihood technique using momentum-weighted charge from the two hemispheres in each tagged event. From our 1994-1995 sample of 3.6 pb−1, having a luminosity-weighted average e− polarization of 77.3%, and our 1993 sample of 1.8 pb−1, having a luminosity-weighted polarization of 63.1%, we obtain A{sub b} = 0.848 " 0.046(stat.) " 0.050(syst.).

Download or read book Measurement of sin 2 theta rm Eff ell and Z light Quark Couplings Using the Forward backward Charge Asymmetry in p bar p to Z gamma to E e Events with cal L written by and published by . This book was released on 2011 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: We measure the mass dependence of the forward-backward charge asymmetry in 157,553 p{bar p} → Z/[gamma]* → e+e− interactions, corresponding to 5.0 fb−1 of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron Collider at √s = 1.96 TeV. The effective weak mixing angle ([theta]{sub eff}{sup {ell}}) from this process involving predominantly the first generation of quarks is extracted as sin2 [theta]{sub eff}{sup {ell}} = 0.2309 ± 0.0008 (stat.) ± 0.0006 (syst.). We also present the most precise direct measurement of the vector and axial-vector couplings of u and d quarks to the Z boson.

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1995 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Drell Yan Differential Cross Section and Forward backward Asymmetry in Pp right Arrow E E Events Using the D Detector written by Raymond Gelhaus and published by . This book was released on 2005 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of Sin2 leff and Z light Quark Couplings Using the Forward backward Charge Asymmetry in Pp Z gamma E e Events with L written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We measure the mass dependence of the forward-backward charge asymmetry in 157,553 pp = Z/?* = e+e- interactions, corresponding to 5.0 fb-1 of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron Collider at √s = 1.96 TeV. The effective weak mixing angle (?leff) from this process involving predominantly the first generation of quarks is extracted as sin2 ?leff = 0.2309 ± 0.0008 (stat.) ± 0.0006 (syst.). We also present the most precise direct measurement of the vector and axial-vector couplings of u and d quarks to the Z boson.

Download or read book Measurement of the Drell Yan Differential Cross Section and Forward Backward Asymmetry in Proton Anti proton E E Events Using the D0 Detector written by Raymond Gelhaus and published by . This book was released on 2005 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present measurements of the inclusive Drell-Yan e{sup +}e{sup -} differential cross section (d{sigma}/dM{sub e{sup +}e{sup -}}) and forward-backward asymmetry (A{sub FB}) as a function of the dielectron invariant mass over the range 70-400 GeV/c{sup 2}. The data sample consists of 177.3 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV collected by the D0 detector. The results are consistent with the predictions of the standard model.

Download or read book A Measurement of the Cross section and Forward backward Asymmetry of the written by Julia Ann Davies and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the forward backward charge asymmetry in electron positron annihilation into a quark antiquark pair a test of electroweak interference by David Donald Stuart written by David D. Stuart and published by . This book was released on 1992 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: