Download or read book Measurement of the Top Quark Mass in P Anti p Collisions at S 1 2 written by and published by . This book was released on 2006 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report the first measurement of the top quark mass using the decay length technique in p{bar p} collisions at a center-of-mass energy of 1.96 TeV. This technique uses the measured flight distance of the b hadron to infer the mass of the top quark in lepton plus jets events with missing transverse energy. It relies solely on tracking and avoids the jet energy scale uncertainty that is common to all other methods used so far. We apply our novel method to a 695 pb−1 data sample recorded by the CDF II detector at Fermilab and extract a measurement of m{sub t} = 180.7{sub -13.4}{sup +15.5}(stat.) ± 8.6 (syst.) GeV/c2. While the uncertainty of this result is larger than that of other measurements, the dominant uncertainties in the decay length technique are uncorrelated with those in other methods. This result can help reduce the overall uncertainty when combined with other existing measurements of the top quark mass.
Download or read book Measurement of the Top Quark Mass in P Anti p Collisions at S written by and published by . This book was released on 2006 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report the first measurement of the top quark mass using the decay length technique in p{bar p} collisions at a center-of-mass energy of 1.96 TeV. This technique uses the measured flight distance of the b hadron to infer the mass of the top quark in lepton plus jets events with missing transverse energy. It relies solely on tracking and avoids the jet energy scale uncertainty that is common to all other methods used so far. We apply our novel method to a 695 pb−1 data sample recorded by the CDF II detector at Fermilab and extract a measurement of m{sub t} = 180.7{sub -13.4}{sup +15.5}(stat.) ± 8.6 (syst.) GeV/c2. While the uncertainty of this result is larger than that of other measurements, the dominant uncertainties in the decay length technique are uncorrelated with those in other methods. This result can help reduce the overall uncertainty when combined with other existing measurements of the top quark mass.
Download or read book Measurement of the Top Quark Pair Production Cross Section in P Anti p Collisions at S 1 2 written by Gustavo J. Otero y Garzon and published by . This book was released on 2006 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subject of this thesis is the measurement of the rate at which a top-antitop quark pair is produced in pp collisions at a center of mass energy of ps = 1:96 TeV. The data are collected with the D detector, a multi-purpose detector operating at the Fermilab Tevatron collider during Run II. A measurement of the top quark pair (t$\bar{t}$) production cross section ( [sigma]t$\bar{t}$) in p$\bar{p}$ collisions at a center of mass energy of 1.96 TeV is presented. The measurement is based on data recorded by the D0 Detector at the Fermilab Tevatron Collider, and preselected in the e+jets (366 pb-1) and [mu]+jets (363 pb-1) channels. The cross section is extracted by applying a lifetime-tagging technique to the data, and yields [sigma]t$\bar{t}$ = 6.96$+1.07\atop{-0.98}$(stat + syst) ± 0.45(lumi) pb; for a top quark mass mt =175 GeV, in good agreement with the Standard Model prediction.
Download or read book Measurement of the Top Quark Mass Using Template Methods on Dilepton Events in P Anti p Collisions at S 1 2 written by and published by . This book was released on 2006 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors describe a measurement of the top quark mass from events produced in p{bar p} collisions at a center-of-mass energy of 1.96 TeV, using the Collider Detector at Fermilab. They identify t{bar t} candidates where both W bosons from the top quarks decay into leptons (e[nu], [mu][nu], or [tau][nu]) from a data sample of 360 pb−1. The top quark mass is reconstructed in each event separately by three different methods, which draw upon simulated distributions of the neutrino pseudorapidity, t{bar t} longitudinal momentum, or neutrino azimuthal angle in order to extract probability distributions for the top quark mass. For each method, representative mass distributions, or templates, are constructed from simulated samples of signal and background events, and parameterized to form continuous probability density functions. A likelihood fit incorporating these parameterized templates is then performed on the data sample masses in order to derive a final top quark mass. Combining the three template methods, taking into account correlations in their statistical and systematic uncertainties, results in a top quark mass measurement of 170.1 ± 6.0(stat.) ± 4.1(syst.) GeV/c2.
Download or read book Measurement of the Top Quark Pair Production Cross Section in P Anti p Collisions at u221A s written by and published by . This book was released on 2006 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subject of this thesis is the measurement of the rate at which a top-antitop quark pair is produced in pp collisions at a center of mass energy of ps = 1:96 TeV. The data are collected with the D detector, a multi-purpose detector operating at the Fermilab Tevatron collider during Run II. A measurement of the top quark pair (t$\bar{t}$) production cross section ( ?t$\bar{t}$) in p$\bar{p}$ collisions at a center of mass energy of 1.96 TeV is presented. The measurement is based on data recorded by the D0 Detector at the Fermilab Tevatron Collider, and preselected in the e+jets (366 pb-1) and ?+jets (363 pb-1) channels. The cross section is extracted by applying a lifetime-tagging technique to the data, and yields ?t$\bar{t}$ = 6.96$+1.07\atop{-0.98}$(stat + syst) ± 0.45(lumi) pb; for a top quark mass mt =175 GeV, in good agreement with the Standard Model prediction.
Download or read book Measurement of the Top Quark Mass with the Dynamical Likelihood Method Using Lepton Plus Jets Events with B tags in P Anti p Collisions at S 1 2 written by and published by . This book was released on 2005 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes a measurement of the top quark mass, M{sub top}, with the dynamical likelihood method (DLM) using the CDF II detector at the Fermilab Tevatron. The Tevatron produces top/anti-top (t{bar t}) pairs in p{bar p} collisions at a center-of-mass energy of 1.96 TeV. The data sample used in this analysis was accumulated from March 2002 through August 2004, which corresponds to an integrated luminosity of 318 pb−1. They use the t{bar t} candidates in the ''lepton+jets'' decay channel, requiring at least one jet identified as a b quark by finding an displaced secondary vertex. The DLM defines a likelihood for each event based on the differential cross section as a function of M{sub top} per unit phase space volume of the final partons, multiplied by the transfer functions from jet to parton energies. The method takes into account all possible jet combinations in an event, and the likelihood is multiplied event by event to derive the top quark mass by the maximum likelihood method. Using 63 t{bar t} candidates observed in the data, with 9.2 events expected from background, they measure the top quark mass to be 173.2{sub -2.4}{sup +2.6}(stat.) ± 3.2(syst.) GeV/c2, or 173.2{sub -4.0}{sup +4.1} GeV/c2.
Download or read book Measurement of the T Anti t Production Cross Section in P Anti p Collisions at S 1 2 written by and published by . This book was released on 2007 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the top quark pair production cross section in p{bar p} collisions at √s = 1.96 TeV utilizing 425 pb−1 of data collected with the D0 detector at the Fermilab Tevatron Collider. We consider the final state of the top quark pair containing one high-p{sub T} electron or muon and at least four jets. We exploit specific kinematic features of t{bar t} events to extract the cross section. For a top quark mass of 175 GeV, we measure [sigma]{sub t{bar t}} = 6.4{sub -1.2}{sup +1.3}(stat) ± 0.7(syst) ± 0.4(lum)pb, in good agreement with the standard model prediction.
Download or read book Measurement of the Top quark Mass in All hadronic Decays in P Anti p Collisions at CDF II written by and published by . This book was released on 2006 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the top-quark mass, M{sub tpo}, in the all-hadronic decay channel t{bar t} --> WbW−{bar b} --> q1{bar q}2bq3{bar q}4{bar b}. The analysis is performed using 310 pb−1 of (square root)s = 1.96 TeV p{bar p} collisions collected with the CDF II detector using a multi-jet trigger. The mass measurement is based on an event-by-event likelihood which depends on both the sample purity and the value of the top-quark mass, using 90 possible jet-to-parton assignments in the six-jet final state. The joint likelihood of 290 selected events yields a value of M{sub top} = 177.1 ± 4.9(stat.) ± 4.7(syst.) GeV/c2.
Download or read book Measurement of the Top Quark Mass in p bar p Collisions Using Events with Two Leptons written by and published by . This book was released on 2012 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the top quark mass (m{sub t}) in p{bar p} collisions at √s = 1.96 TeV using t{bar t} events with two leptons (ee, e? or??) in the final state in 4.3 fb−1 of data collected with the D0 detector at the Fermilab Tevatron collider. We analyze the kinematically underconstrained dilepton events by integrating over the neutrino rapidity distributions. We reduce the dominant systematic uncertainties from jet energy calibration using a correction obtained from t{bar t} → l + jets events. We also correct jets in simulated events to replicate the quark flavor dependence of the jet response in data. In combination with our previous analysis, we measure m{sub t} = 174.0 ± 2.4(stat) ± 1.4(syst) GeV.
Download or read book Measurement of the Tanti t Production Cross Section in P Anti ptnipbar Collisions at S 1 2 written by and published by . This book was released on 2006 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present a measurement of the top quark pair production cross section in p{bar p} collisions at √s = 1.96 TeV using 318 pb−1 of data collected with the Collider Detector at Fermilab. They select t{bar t} decays into the final states e[nu] + jets and [mu][nu] + jets, in which at least one b quark from the t-quark decays is identified using a secondary vertex-finding algorithm. Assuming a top quark mass of 178 GeV/c2, they measure a cross section of 8.7 ± 0.9(stat.){sub -0.9}{sup +1.1}(syst.) pb. They also report the first observation of t{bar t} with significance greater than 5[sigma] in the subsample in which both b quarks are identified, corresponding to a cross section of 10.1{sub -1.4}{sup +1.6}(stat.){sub -1.3}{sup +2.0}(syst.) pb.
Download or read book Precision Top Quark Mass Measurement in the Lepton Jets Topology in P Anti p Collisions at sqrt s written by and published by . This book was released on 2005 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Precision Measurement of the Mass of the Top Quark in P Anti p Collisions written by and published by . This book was released on 2007 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report a measurement of the mass of the top quark (m{sub top}) in p{bar p} collisions at a center of mass energy of 1.96 TeV. The analysis is based on p{bar p}→t{bar t}→ lepton+jets data recorded with the D0 detector at the Fermilab Tevatron Collider. Events were preselected in the e+jets (913 events/pb of data) and in the [mu]+jets (871 events/pb of data) channels. These were analyzed through a comparison of the matrix element for the production and decay of the t{bar t} states with data, using a likelihood method and 'tagged' b quarks from the t → Wb decays.
Download or read book Measurement of the P Anti p T Anti t Production Cross Section at S 1 2 written by and published by . This book was released on 2006 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the top quark pair production cross section in proton anti-proton collisions at an interaction energy of √s = 1.96 TeV is presented. This analysis uses 405 pb−1 of data collected with the D0 detector at the Fermilab Tevatron Collider. Fully hadronic t{bar t} decays with final states of six or more jets are separated from the multijet background using secondary vertex tagging and a neural network. The t{bar t} cross section is measured as [sigma]{sub t{bar t}} = 4.5{sub -1.9}{sup +2.0}(stat){sub -1.1}{sup +1.4}(syst) ± 0.3(lumi) pb for a top quark mass of m{sub t} = 175 GeV/c2.
Download or read book Measurement of the Top Quark Mass Using Template Methods on Dilepton Events in P Anti p Collisions at S written by and published by . This book was released on 2006 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors describe a measurement of the top quark mass from events produced in p{bar p} collisions at a center-of-mass energy of 1.96 TeV, using the Collider Detector at Fermilab. They identify t{bar t} candidates where both W bosons from the top quarks decay into leptons (e?,??, or??) from a data sample of 360 pb−1. The top quark mass is reconstructed in each event separately by three different methods, which draw upon simulated distributions of the neutrino pseudorapidity, t{bar t} longitudinal momentum, or neutrino azimuthal angle in order to extract probability distributions for the top quark mass. For each method, representative mass distributions, or templates, are constructed from simulated samples of signal and background events, and parameterized to form continuous probability density functions. A likelihood fit incorporating these parameterized templates is then performed on the data sample masses in order to derive a final top quark mass. Combining the three template methods, taking into account correlations in their statistical and systematic uncertainties, results in a top quark mass measurement of 170.1 ± 6.0(stat.) ± 4.1(syst.) GeV/c2.
Download or read book Top Quark Pair Production Cross Section Measurements in P Anti p Collisions at S 1 2 written by S. Cabrera and published by . This book was released on 2006 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The CDF and D0 experiments have measured the t{bar t} production cross section in p{bar p} collisions at {radical}s = 1.96 TeV from different final states using a wide variety of techniques. CDF has combined 6 measurements using data samples with integrated luminosities up to 760 pb{sup -1}: {sigma}{sub t{bar t}} = 7.3 {+-} 0.5(stat) {+-} 0.6(syst) {+-} 0.4(lum) pb in good agreement with the theoretical calculations: 6.7 {+-} 0.8 pb for a top mass of 175 GeV/c{sup 2}. The experimental precision of the current CDF combined result is comparable for the first time to the accuracy of the QCD NLO theory: {approx} 12%.
Download or read book Measurement of the Top Quark Mass written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes the measurement of the top quark mass m[sub t] using events recorded during a 125 pb[sup -1] exposure of the D0 detector to[radical]s=1.8 TeV[anti p]p collisions. Six events consistent with the hypothesis t[anti t][yields] bW[sup+], [anti b]W[sup -][yields] b[anti l][nu], [anti b]l[anti[nu]] form the dilepton sample. The kinematics of such events may be reconstructed for any assumed mt, and the likelihood of each such solution evaluated. A measurement of m[sub t] based on these relative solution likelihoods gives m[sub t]= 169.9[+-] 14.8 (stat.)[+-] 3. 8 (syst.) GeV/c[sup 2]. A 2C kinematic fit is performed on a sample of 77 events consistent with t[anti t][yields] bW[sup+], [anti b]W[sup -][yields] b[anti l][nu], [anti b]q[anti q], and this, in combination with an estimate on the likelihood that each event is top, yields m[sub t]= 173.3[+-] 5.6 (stat.)[+-] 6.2 (syst.) GeV/c[sup 2] . A combination of these two measurements gives m[sub t]= 173.1[+-] 5.2 (stat.)[+-] 5.7 (syst.) GeV/c[sup 2].
Download or read book Measurement of the Top Quark Mass Using Charged Particles in Pp Collisions at u221A s written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel technique for measuring the mass of the top quark that uses only the kinematic properties of its charged decay products is presented. Top quark pair events with final states with one or two charged leptons and hadronic jets are selected from the data set of 8 TeV proton-proton collisions, corresponding to an integrated luminosity of 19.7 fb-1. By reconstructing secondary vertices inside the selected jets and computing the invariant mass of the system formed by the secondary vertex and an isolated lepton, an observable is constructed that is sensitive to the top quark mass that is expected to be robust against the energy scale of hadronic jets. The main theoretical systematic uncertainties, concerning the modeling of the fragmentation and hadronization of b quarks and the reconstruction of secondary vertices from the decays of b hadrons, are studied. A top quark mass of 173.68±0.20(stat)-0.97+1.58(syst) GeV is measured. Furthermore, the overall systematic uncertainty is dominated by the uncertainty in the b quark fragmentation and the modeling of kinematic properties of the top quark.
