Download or read book A Measurement of the Production Cross Section of Tt Pairs in Proton antiproton Collisions at square Root s written by Henri Bachacou and published by . This book was released on 2004 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Top Physics written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the t{bar t} production cross section using 194 pb−1 of CDF II data using events with a high transverse momentum electron or muon, three or more jets, and missing transverse energy. The measurement assumes 100% t --> Wb branching fraction. Events consistent with t{bar t} decay are found by identifying jets containing heavy flavor semileptonic decays to muons. The dominant backgrounds are evaluated directly from the data. Based on 20 candidate events and an expected background of 9.5 " 1.1 events, we measure a production cross section of 5.3 " 3.3{sub -1.0}{sup +1.3} pb, in agreement with the standard model.
Download or read book A Measurement of the T T bar Production Cross Section in Proton antiproton Collisions at Sqrt s written by Markus Klute and published by . This book was released on 2004 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Measurement of the Tt Production Cross Section in Proton antiproton Collisions at square Root S written by Markus Klute and published by . This book was released on 2004 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Ttbar Production Cross Section in Ppbar Collisions at Sqrt s written by and published by . This book was released on 2010 with total page 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 using a data sample corresponding to 1.7 fb−1 of integrated luminosity collected with the Collider Detector at Fermilab. We reconstruct t{bar t} events in the lepton+jets channel, consisting of e[nu]+jets and [mu][nu]+jets final states. The dominant background is the production of W bosons in association with multiple jets. To suppress this background, we identify electrons from the semileptonic decay of heavy-flavor jets ('soft electron tags'). From a sample of 2196 candidate events, we obtain 120 tagged events with a background expectation of 51 ± 3 events, corresponding to a cross section of [sigma]{sub t{bar t}} = 7.8 ± 2.4 (stat) ± 1.6 (syst) ± 0.5 (lumi) pb. We assume a top-quark mass of 175 GeV/c2. This is the first measurement of the t{bar t} cross section with soft electron tags in Run II of the Tevatron.
Download or read book Measurement of the Ttbar Production Cross Section in the All jets Final State in Pp Collisions at sqrt s written by and published by . This book was released on 2015 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cross section for tt production in the all-jets final state is measured in pp collisions at a centre-of-mass energy of 8 TeV at the LHC with the CMS detector, in data corresponding to an integrated luminosity of 18.4 fb-1. The inclusive cross section is found to be 275.6 ±6.1 (stat) ± 37.8 (syst) ± 7.2 (lumi) pb. The normalized differential cross sections are measured as a function of the top quark transverse momenta, pT, and compared to predictions from quantum chromodynamics. The results are reported at detector, parton, and particle levels. In all cases, the measured top quark pT spectra are significantly softer than theoretical predictions.
Download or read book Measurement of the ttbar Production Cross Section in 2 Fb 1 of ppbar Collisions at sqrt s written by and published by . This book was released on 2009 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the t{bar t} production cross section in p{bar p} collisions at (square root)s = 1.96 TeV using events containing a high transverse momentum electron or muon, three or more jets, and missing transverse energy. Events consistent with t{bar t} decay are found by identifying jets containing candidate heavy-flavor semileptonic decays to muons. The measurement uses a CDF Run II data sample corresponding to 2 fb−1 of integrated luminosity. Based on 248 candidate events with three or more jets and an expected background of 79.5 ± 5.3 events, we measure a production cross section of 9.1 ± 1.6 pb.
Download or read book Measurement of the Ttbar Production Cross Section in the MET jets Channel at CDF written by and published by . This book was released on 2008 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is focused on an inclusive search of the t{bar t} --> E{sub T} + jets decay channel by means of neural network tools in proton antiproton collisions at (square root)s = 1.96 TeV recorded by the Collider Detector at Fermilab (CDF). At the Tevatron p{bar p} collider top quarks are mainly produced in pairs through quark-antiquark annihilation and gluon-gluon fusion processes; in the Standard Model description, the top quark then decays to a W boson and a b quark almost 100% of the times, so that its decay signatures are classified according to the W decay modes. When only one W decays leptonically, the t{bar t} event typically contains a charged lepton, missing transverse energy due to the presence of a neutrino escaping from the detector, and four high transverse momentum jets, two of which originate from b quarks. In this thesis we describe a t{bar t} production cross section measurement which uses data collected by a 'multijet' trigger, and selects this kind of top decays by requiring a high-P{sub T} neutrino signature and by using an optimized neural network to discriminate top quark pair production from backgrounds. In Chapter 1, a brief review of the Standard Model of particle physics will be discussed, focusing on top quark properties and experimental signatures. In Chapter 2 will be presented an overview of the Tevatron accelerator chain that provides p{bar p} collisions at the center-of-mass energy of (square root)s = 1.96 TeV, and proton and antiproton beams production procedure will be discussed. The CDF detector and its components and subsystems used for the study of p{bar p} collisions provided by the Tevatron will be described in Chapter 3. Chapter 4 will detail the reconstruction procedures used in CDF to detect physical objects exploiting the features of the different detector subsystems. Chapter 5 will provide an overview of the main concepts regarding Artificial Neural Networks, one of the most important tools we will use in the analysis. Chapter 6 will be devoted to the description of the main characteristics of the t{bar t} --> E{sub T} + jets decay channel used to train our neural network to discriminate the top pair production from background processes. We will discuss the event selection method and the technique used for background prediction, that will rely on b-jets identification rate parameterization. Finally, Chapter 7 will provide a description of the final data sample and a detailed discussion of the systematic uncertainties before determining the cross section measurement by means of a likelihood maximization.
Download or read book Measurement of the t bar t Production Cross Section in Pp Collisions at sqrt s written by and published by . This book was released on 2014 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: The top-quark pair production cross section is measured in final states with one electron or muon and one hadronically decaying [tau] lepton from the process $t\bar{t}$ to (l[nu]l) ([tau][nu][tau]) $b\bar{b}$, where l = e, [mu]. The data sample corresponds to an integrated luminosity of 19.6 fb-1 collected with the CMS detector in proton-proton collisions at $\sqrt{s}$ =8 TeV. The measured cross section [sigma]$t\bar{t}$ = 257 ± 3 (stat) ± 24 (syst) ± 7 (lumi) pb, assuming a top-quark mass of 172.5 GeV, is consistent with the standard model prediction.
Download or read book Measurement of Tt Production Cross Section in Pp Collisions at square Root S written by Harpreet Singh and published by . This book was released on 1999 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the t bar t Production Cross Section Using Events with One Lepton and at Least One Jet in Pp Collisions at sqrt s written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the $\mathrm{ t \bar{t} }$ production cross section at $\sqrt{s}=$ 13 TeV is presented using proton-proton collisions, corresponding to an integrated luminosity of 2.3 fb$^{-1}$, collected with the CMS detector at the LHC. Final states with one isolated charged lepton (electron or muon) and at least one jet are selected and categorized according to the accompanying jet multiplicity. From a likelihood fit to the invariant mass distribution of the isolated lepton and a jet identified as coming from the hadronization of a bottom quark, the cross section is measured to be $\sigma(\mathrm{ t \bar{t} })=$ 835 $\pm$ 3 (stat) $\pm$ 23 (syst) $\pm$ 23 (lumi) pb, in agreement with the standard model prediction. Using the expected dependence of the cross section on the pole mass of the top quark ($m_{\mathrm{ t }}$), the value of $m_{\mathrm{ t }}$ is found to be 172.7$^{+2.4}_{-2.7}$ GeV.
Download or read book Measurement of the B c pm Production Cross Section in p bar p Collisions at sqrt s written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Here, we describe a measurement of the ratio of the cross sections times branching fractions of the Bc+ meson in the decay mode Bc+ → J/[psi][mu]+[nu] to the B+ meson in the decay mode B+ → J/[psi]K+ in proton-antiproton collisions at center-of-mass energy √s = 1.96 TeV. The measurement is based on the complete CDF Run II data set, which comes from an integrated luminosity of 8.7 fb-1. The ratio of the production cross sections times branching fractions for Bc+ and B+ mesons with momentum transverse to the beam greater than 6 GeV/c and rapidity magnitude smaller than 0.6 is 0.211 ± 0.012(stat)-0.020+0.021(syst). Using the known B+ → J/[psi]K+ branching fraction, the known B+ production cross section, and a selection of the predicted Bc+ → J/[psi][mu]+[nu] branching fractions, the range for the total Bc+ production cross section is estimated.
Download or read book A Measurement of the T Anti t Production Cross section in Proton Anti proton Collisions at S 1 2 written by Markus Klute and published by . This book was released on 2004 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: A preliminary measurement of the t{bar t} production cross section at {radical}s = 1.96 TeV is presented. The {mu}-plus-jets final state is analyzed in a data sample of 94 pb{sup -1} and a total of 14 events are selected with a background expectation of 11.7 {+-} 1.9 events. The measurement yields: {sigma}{sub p{bar p} {yields} t{bar t} + X} = 2.4{sub -3.5}{sup +4.2}(stat.){sub -2.6}{sup +2.5}(syst.) {+-} 0.3(lumi.) pb. The analysis, being part of a larger effort to re-observe the top quark in Tevatron Run II data and to measure the production cross section, is combined with results from all available analyses channels. The combined result yields: {sigma}{sub p{bar p}} {yields} t{bar t} + X = 8.1{sub -2.0}{sup +2.2}(stat.){sub -1.4}{sup +1.6}(syst.) {+-} 0.8(lumi.) pb.
Download or read book Measurement of the P Anti p T Anti t Production Cross Section at S 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?{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 A Measurement of the Tt Production Cross Section in Proton Antiproton Collisions at s written by Markus Klute and published by . This book was released on 2004 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Top Physics written by and published by . This book was released on 2005 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the t{bar t} production cross section using events with one charged lepton and jets from p{bar p} collisions at a center-of-mass energy of 1.96TeV. In these events, heavy flavor quarks from top quark decay are identified with a secondary vertex tagging algorithm. From 162 pb−1 of data collected by the Collider Detector at Fermilab, a total of 48 candidate events are selected, where 13.5 ± 1.8 events are expected from background contributions. We measure a t{bar t} production cross section of 5.6{sub -1.1}{sup _1.2}(stat.){sub -0.6}{sup +0.9}(syst.)pb.
Download or read book Measurement of the Top Pair production Cross Section in the Dilepton Channel in Proton antiproton Collisions at square Root S written by Mircea Norocel Coca and published by . This book was released on 2005 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:
