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Book Measurement of Top Anti top Cross Section in Proton   Anti proton Collider at S   1 2

Download or read book Measurement of Top Anti top Cross Section in Proton Anti proton Collider at S 1 2 written by Prolay Kumar Mal and published by . This book was released on 2005 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discovery of the top quark in 1995 at the Fermilab Tevatron collider concluded a long search following the 1977 discovery of bottom (b) quark [1] and represents another triumph of the Standard Model (SM) of elementary particles. Top quark is one of the fundamental fermions in the Standard Model of electroweak interactions and is the weak-isospin partner of the bottom quark. A precise measurement of top pair production cross-section would be a test of Quantum Chromodynamics (QCD) prediction. Presently, Tevatron is the world's highest energy collider where protons (p) and anti-protons ({anti p}) collide at a centre of mass energy (ps) of 1.96 TeV. At Tevatron top (t) and anti-top ({anti t}) quarks are predominantly pair produced through strong interactions--quark annihilation ({approx_equal} 85%) and gluon fusion ({approx_equal} 15%). Due to the large mass of top quark, t or {anti t} decays ({approx} 10{sup -25} sec) before hadronization and in SM framework, it decays to a W boson and a b quark with {approx} 100% branching ratio (BR). The subsequent decay of W boson determines the major signatures of t{anti t} decay. If both W bosons (coming from t and {anti t} decays) decay into leptons (viz., ev{sub e}, {mu}{nu}{sub {mu}} or {tau}{nu}{sub {tau}}) the corresponding t{bar t} decay is called dileptonic decay. Of all dileptonic decay modes of t{bar t}, the t{bar t} {yields} WWb{anti b} {yields} ev{sub e}{mu}{nu}{sub {mu}}b{anti b} (e{mu} channel) decay mode has the smallest background contamination from Z{sup 0} production or Drell-Yan process; simultaneously, it has the highest BR ({approx} 3.16%) [2] amongst all dileptonic decay modes of t{bar t}. During Run I (1992-1996) of Tevatron, three e{mu} candidate events were detected by D0 experiment, out of 80 candidate events (inclusive of all decay modes of t{bar t}). Due to the rarity of the t{bar t} events, the measured cross-section has large uncertainty in its value (viz., 5.69 {+-} 1.21(stat) {+-} 1.04(sys) pb {at} {radical}s = 1.8 TeV measured by D0 [3]). This analysis presents a cross section measurement in e{mu} channel utilizing {approx} 228 pb{sup -1} of data collected by D0 experiment during Tevatron Run II (between June 2002 and April 2004).

Book Measurement of the P Anti p     T Anti t Production Cross Section at S

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.

Book Small T Physics at the Tevatron Collider

Download or read book Small T Physics at the Tevatron Collider written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The first physics run of the superconducting Tevatron Collider at Fermilab ended this morning. A status report will be presented on the progress of the small angle elastic scattering and total cross section experiment, E710. The goals of this experiment are to measure the total proton-antiproton cross section from .sqrt.s = 300 to 2000 GeV, the slope of the diffraction peak and rho, the ratio of the real to imaginary part of the forward scattering amplitude, at these energies. 1 ref., 8 figs.

Book Proton antiproton Collider Physics   8th Topical Workshop

Download or read book Proton antiproton Collider Physics 8th Topical Workshop written by G Belletini and published by World Scientific. This book was released on 1990-07-19 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proceedings presents in a systematic way Top searches, Jets, Gauge Boson production, precision tests of electroweak theory, Ln s Physics, heavy Flavours and exotics. In addition, contributions to the sessions 'News from the World', 'Short term future' and 'Long term future' show the progress of SSC in USA, of LHC at CERN, UNK/VLEPP in USSR together with Perspectives of Hadron Collider Physics.

Book Measurement of the Single Top Production Cross Section in Proton antiproton Collisions at 1 96 TeV

Download or read book Measurement of the Single Top Production Cross Section in Proton antiproton Collisions at 1 96 TeV written by and published by . This book was released on 2010 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes a search for singly produced top quarks via an electroweak vertex in head-on proton-antiproton collisions at a center of mass energy of √s = 1.96 TeV. The analysis uses a total of 2.3 fb−1 of data collected with the D0 detector at Fermilab, corresponding to two different run periods of the Tevatron collider. Two channels contribute to single top quark production at the Tevatron, the s-channel and the t-channel. In the s-channel, a virtual W boson is produced from the aniquilation of a quark and an antiquark and a top and a bottom quarks are produced from the W decay. The top quark decays almost exclusively into a W boson and a bottom quark. Final states are considered in which the W boson decays leptonically into an electron or a muon plus a neutrino. Thus, at the detector level, the final state characterizing the s-channel contains one lepton, missing energy accounting for the neutrino, and two jets from the two bottom quarks. In the t-channel, the final state has an additional jet coming from a light quark. Clearly, a precise reconstruction of the events requires a precise measurement of the energy of the jets. A multivariate technique, Bayesian neural networks, is used to extract the single top signal from the overwhelming background still left after event selection. A Bayesian likelihood probability is then computed to measure the single top cross section. Assuming the observed excess is due to single top events, the measured single top quark production cross section is [sigma](p{bar p} → tb + X, tqb + X) = 4.70{sub -0.93}{sup +1.18} pb. The observed excess is associated with a p-value of (3.2 ± 2.3) x 10−8, assuming the background-only hypothesis. This p-value corresponds to an excess over background of 5.4 standard deviations for a Gaussian density. The p-value computed using the standard model signal cross section of 3.46 pb is (22.7 ± 0.6) x 10−6, corresponding to an expected significance of 4.08 standard deviations.

Book Proton antiproton Collider Physics

Download or read book Proton antiproton Collider Physics written by G. Altarelli and published by World Scientific. This book was released on 1989 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume reviews the physics studied at the CERN proton-antiproton collider during its first phase of operation, from the first physics run in 1981 to the last one at the end of 1985.The volume consists of a series of review articles written by physicists who are actively involved with the collider research program. The first article describes the proton-antiproton collider facility itself, including the antiproton source and its principle of operation based on stochastic cooling.The subsequent six articles deal with the various physics subjects studied at the collider. Each article describes in detail the experimental results on a particular subject, and also provides the theoretical framework necessary for their interpretation. Finally the last two articles discuss the physics expectations from the improved collider (the so-called ACOL program, which has just started operation), and also from the next generation of ?supercolliders? which are being considered both in Europe and in the United States America.

Book Measurement of the P Anti p     T Anti t Production Cross Section at S  1 2

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.

Book Measurement of Top Anti top Cross Section in Proton   Anti proton Collider at  u221A s

Download or read book Measurement of Top Anti top Cross Section in Proton Anti proton Collider at u221A s written by and published by . This book was released on 2005 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discovery of the top quark in 1995 at the Fermilab Tevatron collider concluded a long search following the 1977 discovery of bottom (b) quark [1] and represents another triumph of the Standard Model (SM) of elementary particles. Top quark is one of the fundamental fermions in the Standard Model of electroweak interactions and is the weak-isospin partner of the bottom quark. A precise measurement of top pair production cross-section would be a test of Quantum Chromodynamics (QCD) prediction. Presently, Tevatron is the world's highest energy collider where protons (p) and anti-protons ($ar{p}$) collide at a centre of mass energy √s of 1.96 TeV. At Tevatron top (t) and anti-top ($ar{t}$) quarks are predominantly pair produced through strong interactions--quark annihilation (≅ 85%) and gluon fusion (≅ 15%). Due to the large mass of top quark, t or $ar{t}$ decays ( ̃10-25 sec) before hadronization and in SM framework, it decays to a W boson and a b quark with ̃100% branching ratio (BR). The subsequent decay of W boson determines the major signatures of t$ar{t}$ decay. If both W bosons (coming from t and $ar{t}$ decays) decay into leptons (viz., eve, ?v? or ?c?) the corresponding t$ar{t}$ decay is called dileptonic decay. Of all dileptonic decay modes of t$ar{t}$, the t$ar{t}$ → WWb$ar{b}$ → eve?v?b$ar{b}$ (e? channel) decay mode has the smallest background contamination from Z0 production or Drell-Yan process; simultaneously, it has the highest BR ( ̃3.16%) [2] amongst all dileptonic decay modes of t$ar{t}$. During Run I (1992-1996) of Tevatron, three e? candidate events were detected by D0 experiment, out of 80 candidate events (inclusive of all decay modes of t$ar{t}$). Due to the rarity of the t$ar{t}$ events, the measured cross-section has large uncertainty in its value (viz., 5.69 ± 1.21(stat) ± 1.04(sys) pb @ √s = 1.8 TeV measured by D0 [3]). This analysis presents a cross section measurement in e? channel utilizing ̃228 pb-1 of data collected by D0 experiment during Tevatron Run II (between June 2002 and April 2004).

Book A Measurement of the T Anti t Production Cross section in Proton Anti proton Collisions at S   1 2

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.

Book The Rise of the Proton  anti proton Total Cross Section at Tevatron Energies and Beyond

Download or read book The Rise of the Proton anti proton Total Cross Section at Tevatron Energies and Beyond written by P. M. Kluit and published by . This book was released on 1987 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Measurement of the T Anti t Production Cross Section in P Anti p Collisions at S   1 2

Download or read book Measurement of the T Anti t Production Cross Section in P Anti p Collisions at S 1 2 written by Heather Lynn Ray and published by . This book was released on 2004 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: The direct observation of the top quark was first achieved at the Tevatron proton anti-proton collider at Fermilab. This discovery completed the third generation quark sector where the top quark is expected to accompany the bottom quark in the weak isospin doublet. This dissertation discusses the experimental verification of the production cross section as predicted by the Standard Model. A measurement of the t{bar t} production cross section using 107.9 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV collected with the Collider Detector at Fermilab between March of 2003 and June of 2003 is presented. The measurement focuses on the t{bar t} production in the ''lepton plus jets'' final state in which one of the W bosons from the t{bar t} decay subsequently decays leptonically to an electron or a muon, and the other decays hadronically. The B-tagging technique which utilizes the precision silicon detector tracking is used to enhance the signal for t{bar t} events relative to the background through identification of the bottom quark from its measurable lifetime. The t{bar t} production cross section is measured to be {sigma}{sub t{bar t}} = 4.5 {+-} 1.4(stat) {+-} 0.8(sys) pb.

Book Top Quark Pair Production Cross Section at the Tevatron

Download or read book Top Quark Pair Production Cross Section at the Tevatron written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The top quark, discovered in 1995 by the CDF and D0 collaborations at the Tevatron proton antiproton collider at Fermilab, has undergone intense studies in the last 20 years. Currently, CDF and D0 converge on their measurements of top-antitop quark production cross sections using the full Tevatron data sample. In these proceedings, the latest results on inclusive and differential measurements of top-antitop quark production cross sections at the Tevatron are reported.

Book Measurement of the Inclusive Isolated Prompt Photon Cross Section in  p bar p   Collisions Using the Full CDF Data Set

Download or read book Measurement of the Inclusive Isolated Prompt Photon Cross Section in p bar p Collisions Using the Full CDF Data Set 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 inclusive production cross section of isolated prompt photons in proton-antiproton collisions at center-of-mass energy $\sqrt{s}$=1.96TeV is presented. The results are obtained using the full Run II data sample collected with the Collider Detector at the Fermilab Tevatron, which corresponds to an integrated luminosity of 9.5fb$^{-1}$. The cross section is measured as a function of photon transverse energy, $E_T^{\gamma}$, in the range 30$