Download or read book A Measurement of Z Boson Production and Rapidity Distribution in Proton Antiproton Collisions at u221A s written by and published by . This book was released on 2004 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-precision measurements are made of Z boson production in proton-antiproton collisions at √s = 1.96 TeV recorded by the Collider Detector at Fermilab, using the electron decay channel. The cross-section times branching ratio is measured to be ?Z · Br(Z → e+e-) = (255.7 ± 2.4stat ± 5.2sys ± 15.2lum)pb in a dataset of 194 pb-1 collected between March 2002 and June 2003. This agrees well with theoretical predictions. The cross-section for W boson production in the electron channel has also been measured in the subset of this dataset of 72 pb-1 collected up until January 2003. Using this smaller dataset the ratio of cross-sections is determined to be R ≡ ?W · Br(W → e?)/?Z · Br(Z → ee) = 10.82 ± 0.18stat ± 0.16sys. Combining these results with measurements made in the muon channel gives R = 10.92 ± 0.15stat ± 0.14sys (e + ? channels), from which the branching ratio of the W to electrons and muons, and the total width of the W, have been extracted: Br(W → l?) = 0.1089 ± 0.0022 (l = e,?); ?(W) = 2078.8 ± 41.4 MeV, which are in good agreement with the Standard Model values and with other measurements. The CKM quark mixing matrix element.
Download or read book A Measurement of Z Boson Production and Rapidity Distribution in Proton antiproton Collisions at square Root of S written by Aidan Robson and published by . This book was released on 2004 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Measurement of Z Boson Production and Rapidity Distribution in P Anti p Collisions at S 1 2 written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract Not Provided.
Download or read book Measurement of the Z Boson Differential Cross Section in Transverse Momentum and Rapidity in Proton proton Collisions at 8 TeV written by and published by . This book was released on 2015 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the Z boson differential cross section in rapidity and transverse momentum using a data sample of pp collision events at a centre-of-mass energy √s=8 TeV, corresponding to an integrated luminosity of 19.7 fb-1. The Z boson is identified via its decay to a pair of muons. The measurement provides a precision test of quantum chromodynamics over a large region of phase space. In addition, due to the small experimental uncertainties in the measurement the data has the potential to constrain the gluon parton distribution function in the kinematic regime important for Higgs boson production via gluon fusion. The results agree with the next-to-next-to-leading-order predictions computed with the fewz program. The results are also compared to the commonly used leading-order MadGraph and next-to-leading-order powheg generators.
Download or read book Measurement of Z Boson Transverse Momentum in Proton Anti proton Collisions at u221A s written by and published by . This book was released on 2007 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes a measurement of the shape of the boson transverse momentum distribution in p$ar{p}$ → Z/?* → e+e- + X events at a center-of-mass energy of 1.96 TeV. The measurement is made for events with electron-positron mass between 70 Msubee/sub 110 GeV/csup2/sup and uses 976 pb
Download or read book Measurement of Z Boson Transverse Momentum in Proton antiproton Collisions at Sqrt s written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Measurement of the W Boson Mass in Proton antiproton Collisions at a Center of Mass Energy of 1 8 TeV written by Eric Michael Flattum and published by . This book was released on 1996 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of W and Z Boson Production and Extraction of the W Width and Branching Ratios at CDF written by and published by . This book was released on 1994 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present results from W and Z boson production in proton-antiproton collisions at √s = 1.8 TeV using the CDF detector. We measure the W and Z cross sections times lepton branching ratio, [sigma](p{bar p} → W)·B(W → l[nu]{sub l}) and [sigma](p {bar p} → Z)· B(Z → k+l−) l = e, [mu]. We also measure the ratio: R{sub l} = [sigma] · B(W → l[nu]{sub l})/[sigma] · B(Z → ll). From R{sub l}, we extract the W electron and muon branching ratios, BR(W → l[nu]{sub l}, and the total W width, [Gamma]{sub W}. In addition, high transverse mass W →e[nu]{sub e}, candidates provide an alternate, direct measurement of [Gamma]{sub W}.
Download or read book Measurement of Z Boson Transverse Momentum in Proton Anti proton Collisions at S 1 2 written by and published by . This book was released on 2007 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes a measurement of the shape of the boson transverse momentum distribution in p{bar p} 2!Z/[gamma]* 2!ee− + X events at a center-of-mass energy of 1.96 TeV. The measurement is made for events with electron-positron mass between 70
Download or read book Diffractive Z u2192 Boson Production in Proton Antiproton Collisions At u221A s written by and published by . This book was released on 2007 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of the inclusive diffractive Z → ?+?- cross section with gap requirement for M?? > 40 GeV at √s = 1.96 TeV and fraction of Z bosons produced diffractively with gap requirement from Z inclusive production are presented. The measurements are performed using a data sample corresponding to an integrated luminosity of 820 pb-1, collected with the D0 detector at the Tevatron, between 2002 to 2005. A total of 39945 di-muons events are selected and final results of: ?$gaptop{Diff}$ x Br(Z/?* → ?+?-) = 4.09 ± 0.64(stat.) ± 0.88(syst.) ± 0.27(lumi.) pb and, R$gaptop{Diff}$ = 1.92 ± 0.30(stat.) ± 0.41(syst.) ± 0.12(lumi) % are obtained. In addition, d?/d? and d?/dy distributions are presented and they are compared with diffractive montecarlo (POMWIG). A reasonable agreement is obtained in this comparation. Finally, comparison of fraction of Z bosons produced diffractively with gap requirement (gap fraction) as measured with D0 during Run I of the Tevatron is compared. A good agreement is found for gap fraction results.
Download or read book Search for Exclusive Z Boson Production and Observation of High Mass P Anti p Gamma Gamma Anti p Pl L Anti p Events in P Anti p Collisions at S written by and published by . This book was released on 2009 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a search for exclusive Z boson production in proton-antiproton collisions at √s = 1.96 TeV, using the CDF II detector at Fermilab. We observe no exclusive Z → ll− candidates and place the first upper limit on the exclusive Z cross section in hadron collisions,?{sub excl}(Z) 0.96 pb at 95% confidence level. In addition, we observe eight candidate exclusive dilepton events from the quantum electrodynamic process p{bar p} → p??{bar p} → pl+l− {bar p}, and measure the cross section for M{sub l{ell}} 40 GeV=c2 and.
Download or read book Search for Exclusive Z Boson Production and Observation of High Mass P Anti p Gamma Gamma Anti p Pl L Anti p Events in P Anti p Collisions at S 1 2 written by and published by . This book was released on 2009 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a search for exclusive Z boson production in proton-antiproton collisions at √s = 1.96 TeV, using the CDF II detector at Fermilab. We observe no exclusive Z → l+l− candidates and place the first upper limit on the exclusive Z cross section in hadron collisions, [sigma]{sub excl}(Z) 0.96 pb at 95% confidence level. In addition, we observe eight candidate exclusive dilepton events from the quantum electrodynamic process p{bar p} → p[gamma][gamma]{bar p} → pl+l− {bar p}, and measure the cross section for M{sub l{ell}} 40 GeV=c2 and.
Download or read book Search for the Production of ZW and ZZ Boson Pairs Decaying Into Charged Leptons and Jets in Proton antiproton Collisions at Sqrt s written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the production cross section for ZW and ZZ boson pairs in final states with a pair of charged leptons, from the decay of a Z boson, and at least two jets, from the decay of a W or Z boson, using the full sample of proton-antiproton collisions recorded with the CDF II detector at the Tevatron, corresponding to 8.9 fb(̂-1) of integrated luminosity. We increase the sensitivity to vector boson decays into pairs of quarks using a neural network discriminant that exploits the differences between the spatial spread of energy depositions and charged-particle momenta contained within the jet of particles originating from quarks and gluons. Additionally, we employ new jet energy corrections to Monte Carlo simulations that account for differences in the observed energy scales for quark and gluon jets. The number of signal events is extracted through a simultaneous fit to the dijet mass spectrum in three classes of events: events likely to contain jets with a heavy-quark decay, events likely to contain jets originating from light quarks, and events that fail these identification criteria. We determine the production cross section to be 2.5 +2.0 -1.0 pb (
Download or read book Measurement of Z boson Production in Pb Pb and P p Collisions Via the Electron and Muon Decay Channels at squareroot s NN written by Michael David Gardner and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments over the last decade at the Relativistic Heavy Ion Collider (RHIC) at the Brookhaven National Laboratory have yielded evidence for the formation of the new state of matter called the quark-gluon plasma (QGP). Normally, quarks (and their associated gluons) are found only in colorless doublets (mesons) or triplets (baryons), but when raised above the cross-over threshold at a temperature of ∼ 175 MeV, a strongly-coupled partonic medium of asymptotically free quarks and gluons is expected to form. The focus of heavy-ion physics at both the RHIC and Large Hadron Collider (LHC) experiments has been to study physical processes that allow for a better grasp of the properties of this medium. Because of the large center-of-mass energy per nucleon pair ([squareroot]s(NN)) of 2.76 TeV in Pb+Pb collisions at the LHC and substantial delivered integrated luminosities, the study of new processes in nucleus-nucleus collisions has become possible. One of those processes is Z-boson production, which due to it not interacting strongly, being produced in hard collisions and having a decay channel that does not interact with the QGP, can act as a control in understanding the cold nuclear matter effects present in heavy-ion collisions. This dissertation presents the measurement of the production of Z bosons in the dimuon and dielectron decay channels in Pb+Pb and p+p collisions at [squareroot]s(NN) of 2.76 TeV obtained by the CMS experiment at the LHC. The analysis is based on the data sample collected during the Pb+Pb run in 2011, which corresponds to an integrated luminosity of 150 [mu]b−1 and on the p+p data sample collected in 2013, at the same center-of-mass energy, with an integrated luminosity of 5.4 pb−1. The ratio of Pb+Pb to p+p yields, scaled by the number of incoherent nucleon-nucleon collisions, R(AA), is expected to be equal to unity if there are no nuclear effects modifying the production of the Z boson in the Pb+Pb collisions. The R(AA) for centrality-integrated Z-boson production is found to be 1.06 ± 0.05 (stat) ± 0.08 (syst) in the dimuon channel and 1.02 ± 0.08 (stat) ± 0.15 (syst) in the dielectron channel, and shows no nuclear modification across the rapidity, transverse momentum and centrality bins measured. This result demonstrates that the binary-collision scaling is seen to hold in the kinematic region studied, which is expected for a colorless probe that is unaffected by a deconfined QGP. It also opens avenues to study processes that are strongly modified by the QGP, by using Z production as a control.
Download or read book Measurement of the Production Cross section of the Z Boson and Determination of Its Spin with the ATLAS Detector written by Shalu Solomon and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "This thesis presents the results of two measurements of the Z boson, one of the mediators of the electroweak force in the Standard Model of particle physics. The first is the measurement of the total and the differential production cross-sections of the Z boson, and the second is the determination of the spin of the particle. The measurements are made with the 6.1 fb-1 proton-proton collision data collected by the ATLAS detector in 2016 at a center of mass energy of 13 TeV with the Large Hadron Collider. The leptonic decay of the Z boson into an electron-positron pair is the channel examined. The measurements are compared with the theoretical predictions at next-to-leading order for a quantitative and a precise understanding of the process. The observed results agree with the Standard Model expectations within uncertainties. The total cross-section of Z production in the di-electron channel is measured to be 1.878 ± 0.02 (stat)_(−0.052)^(+0.045) (syst) ± 0.042 (lumi) nb and the differential cross-sections as functions of the transverse momentum and the rapidity of the Z particle match with the predictions. The angular distribution of the electrons confirms the spin 1 nature of the Z boson, also in accordance with the Standard Model." --
Download or read book Measurement of the Differential Angular Distribution of the W Boson Produced in Association with Jets in Proton antiproton Collisions at Squareroot s written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Mass and Width of the Z Boson from Z Going to Positron electron Decay in Antiproton proton Collisions at Sqrt s written by Hovhannes Keutelian and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: I report the results of an analysis to measure the mass and width of the Z gauge boson from Z $to$ e$sp{+}$e$sp{-}$ decays in pp collisions at $sqrt{s}$ = 1.8 TeV. The Z $to$ e$sp{+}$e$sp{-}$ data from the CDF detector yields a mass of the Z boson of M$sb{rm Z}$ = 90.78 $pm$ 0.40(stat.) $pm$ 0.38(syst.) $pm$ 0.2(scale) GeV/c$sp2$ and a width of $Gammasb{rm Z}$ = 2.8 $pm$ 1.0(stat.) $pm$ 0.5(syst.) GeV.
