Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Measurement Of The Forward Backward Asymmetry In Top Antitop Quark Events In The Lepton Jets Channel At Do
Download Measurement Of The Forward Backward Asymmetry In Top Antitop Quark Events In The Lepton Jets Channel At Do full books in PDF, epub, and Kindle. Read online Measurement Of The Forward Backward Asymmetry In Top Antitop Quark Events In The Lepton Jets Channel At Do ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Measurement of the Forward-Backward Asymmetry in Top-Antitop Quark Events in the Lepton+Jets Channel at by :
Download or read book Measurement of the Forward-Backward Asymmetry in Top-Antitop Quark Events in the Lepton+Jets Channel at written by and published by . This book was released on 2012 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of forward-backward asymmetries in top-antitop quark pairs produced in proton-antiproton collisions decaying via the lepton+jets channel. Using data recorded by the D0 experiment at the Fermilab Tevatron collider and corresponding to an integrated luminosity of 5.4 fb-1, we measure the forward-backward asymmetry in top-antitop quark events to be $\left(9.2 \pm 3.7\right)\%$, after background processes have been subtracted. After correcting for the effects of acceptance and detector reconstruction, we measure an asymmetry of $\left(19.6 \pm 6.5\right)\%$. In addition, we measure an acceptance-corrected asymmetry based on the lepton from top-antitop quark decay of $\left(15.2 \pm 4.0\right)\%$. We compare these results to predictions from the MC@NLO next-to-leading-order QCD simulation.
Book Synopsis Measurement of the Forward-backward Asymmetry in Top-antitop Quark Events in the Lepton+jets Channel at DØ by : Douglas A. Orbaker
Download or read book Measurement of the Forward-backward Asymmetry in Top-antitop Quark Events in the Lepton+jets Channel at DØ written by Douglas A. Orbaker and published by . This book was released on 2012 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: "We present a measurement of forward-backward asymmetries in top-antitop quark pairs produced in proton-antiproton collisions decaying via the lepton+jets channel. Using data recorded by the DØ experiment at the Fermilab Tevatron collider and corresponding to an integrated luminosity of 5.4 fb -1, we measure the forward-backward asymmetry in top-antitop quark events to be (9.2 ± 3.7)%, after background processes have been subtracted. After correcting for the effects of acceptance and detector reconstruction, we measure an asymmetry of (19.6 ± 6.5)%. In addition, we measure an acceptance-corrected asymmetry based on the lepton from top-antitop quark decay of (15.2 ± 4.0)%. We compare these results to predictions from the mc@nlo next-to-leading-order QCD simulation"--Leaf v.
Book Synopsis Measurement of the Forward-backward Asymmetry in Top Quark-antiquark Production in Ppbar Collisions Using the Lepton+jets Channel by :
Download or read book Measurement of the Forward-backward Asymmetry in Top Quark-antiquark Production in Ppbar Collisions Using the Lepton+jets Channel written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Measurement of the Front Back Asymmetry in Top-Antitop Quark Pairs Produced in Pp Collisions at ?s by : Thomas Andrew Schwarz
Download or read book Measurement of the Front Back Asymmetry in Top-Antitop Quark Pairs Produced in Pp Collisions at ?s written by Thomas Andrew Schwarz and published by . This book was released on 2006 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Forward-Backward Asymmetry of Top Quark Pair Productionn at the Fermilab Tevatron by :
Download or read book Forward-Backward Asymmetry of Top Quark Pair Productionn at the Fermilab Tevatron written by and published by . This book was released on 2015 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents the final measurements of the forward-backward asymmetry (AFB) of top quark-antiquark pair events (t t- ) at the Collider Detector at Fermilab (CDF) experiment. The t t- events are produced in proton{anti-proton collisions with a center of mass energy of 1:96 TeV during the Run II of the Fermilab Tevatron. The measurements are performed with the full CDF Run II data (9.1 fb-1) in the final state that contain two charged leptons (electrons or muons, the dilepton final state), and are designed to con rm or deny the evidence-level excess in the AFB measurements in the final state with a single lepton and hadronic jets (lepton+jets final state) as well as the excess in the preliminary measurements in the dilepton final state with the first half of the CDF Run II data. New measurements include the leptonic AFB (AlFB), the lepton-pair AFB (All FB) and the reconstructed top AFB (At t FB). Each are combined with the previous results from the lepton+jets final state measured at the CDF experiment. The inclusive Al FB, All FB, and At t FB measured in the dilepton final state are 0.072 ± 0.060, 0.076 ± 0.081, and 0.12 ± 0.13, to be compared with the Standard Model (SM) predictions of 0.038 ± 0.003, 0.048 ± 0.004, and 0.010 ± 0.006, respectively. The CDF combination of AlFB and At t FB are 0.090+0:028 -0.026, and 0.160 ± 0.045, respectively. The overall results are consistent with the SM predictions.
Book Synopsis Forward-backward Asymmetry in Top Quark-antiquark Production by :
Download or read book Forward-backward Asymmetry in Top Quark-antiquark Production written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of forward-backward asymmetry in top quark-antiquark production in proton-antiproton collisions in the final state containing a lepton and at least four jets. Using a dataset corresponding to an integrated luminosity of 5.4 fb−1, collected by the D0 experiment at the Fermilab Tevatron Collider, we measure the t{bar t} forward-backward asymmetry to be (9.2 ± 3.7)% at the reconstruction level. When corrected for detector acceptance and resolution, the asymmetry is found to be (19.6 ± 6.5)%. We also measure a corrected asymmetry based on the lepton from a top quark decay, found to be (15.2 ± 4.0)%. The results are compared to predictions based on the next-to-leading-order QCD generator mc@nlo. The sensitivity of the measured and predicted asymmetries to the modeling of gluon radiation is discussed.
Book Synopsis Symmetry in Particle Physics by : Michal Hnatič
Download or read book Symmetry in Particle Physics written by Michal Hnatič and published by MDPI. This book was released on 2021-06-24 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Particle physics is a science about the symmetries of our world. The Standard Model is the fundamental theory of microworld. Particle dynamics in the Standard Model obeys strict symmetry laws with explicit experimental consequences. Priority problems of particle physics based on the Standard Model are more accurate theoretical predictions, experimental measurements and data analysis, proof of existence or non-existence of supersymmetry, top quark properties, Higgs boson, exotic quark states, and physics of neutrinos. In this collection of articles, many of these problems are discussed. We recommend this book for students, graduate students, and scientists working in the field of high energy physics.
Book Synopsis Measurement of the Forward-backward Charge Asymmetry in Electron-positron Annihilation Into a Quark-antiquark Pair by : David Donald Stuart
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:
Book Synopsis A Measurement of the Mass of the Top Quark in Lepton + Jets Events at CDF by : Erik Matthews Brubaker
Download or read book A Measurement of the Mass of the Top Quark in Lepton + Jets Events at CDF written by Erik Matthews Brubaker and published by . This book was released on 2004 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The First Measurement of the Top Quark Mass at CDF II in the Lepton+jets and Dilepton Channels Simultaneously by :
Download or read book The First Measurement of the Top Quark Mass at CDF II in the Lepton+jets and Dilepton Channels Simultaneously written by and published by . This book was released on 2008 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present a measurement of the mass of the top quark using data corresponding to an integrated luminosity of 1.9 fb−1 of p{bar p} collisions collected at (square root)s = 1.96 TeV with the CDF II detector at Fermilab's Tevatron. This is the first measurement of the top quark mass using top-antitop pair candidate events in the lepton + jets and dilepton decay channels simultaneously. They reconstruct two observables in each channel and use a non-parametric kernel density estimation technique to derive two-dimensional probability density functions from simulated signal and background samples. The observables are the top quark mass and the invariant mass of two jets from the W decay in the lepton + jets channel, and the top quark mass and the scalar sum of transverse energy of the event in the diletpon channel. They perform a simultaneous fit for the top quark mass and the jet energy scale, which is constrained in situ by the hadronic W boson mass. using 332 lepton + jets candidate events and 144 diletpon candidate events, they measure the top quark mass to be m{sub top} = 171.9 ± 1.7 (stat. + JES) ± 1.1 (other sys.) GeV/c2 = 171.9 ± 2.0 GeV/c2.
Book Synopsis First Measurement of the Forward-backward Asymmetry in Bottom-quark Pair Production at High Mass by :
Download or read book First Measurement of the Forward-backward Asymmetry in Bottom-quark Pair Production at High Mass written by and published by . This book was released on 2015 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: We measure the particle-level forward-backward production asymmetry in $\mathrm{b\bar{b}}$ pairs with masses (m$\mathrm{b\bar{b}}$) larger than 150 GeV/c2, using events with hadronic jets and employing jet charge to distinguish b from $\bar{b}$. The measurement uses 9.5 fb-1 of $\mathrm{p\bar{p}}$ collisions at a center-of-mass energy of 1.96 TeV recorded by the CDF II detector. The asymmetry as a function of m$\mathrm{b\bar{b}}$ is consistent with zero, as well as with the predictions of the standard model. The measurement disfavors a simple model including an axigluon with a mass of 200 GeV/c2, whereas a model containing a heavier 345 GeV/c2 axigluon is not excluded.
Book Synopsis Measurement of the Front Back Asymmetry in Top-antitop Quark Pairs Produced in Proton-antiproton Collisions at Center of Mass Energy by : Thomas A. Schwarz
Download or read book Measurement of the Front Back Asymmetry in Top-antitop Quark Pairs Produced in Proton-antiproton Collisions at Center of Mass Energy written by Thomas A. Schwarz and published by . This book was released on 2006 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quarks, along with leptons and force carrying particles, are predicted by the Standard Model to be the fundamental constituents of nature. In distinction from the leptons, the quarks interact strongly through the chromodynamic force and are bound together within the hadrons. The familiar proton and neutron are bound states of the light ''up'' and ''down'' quarks. The most massive quark by far, the ''top'' quark, was discovered by the CDF and D0 experiments in March, 1995. The new quark was observed in p{bar p} collisions at 1.8 TeV at the Fermilab Tevatron. The mass of the top quark was measured to be 176 {+-} 13 GeV/c{sup 2} and the cross section 6.8{sub -2.4}{sup +3.6} pb. It is the Q = 2/3, T{sub 3} = +1/2 member of the third generation weak-isospin doublet along with the bottom quark. The top quark is the final Standard Model quark to be discovered. Along with whatever is responsible for electroweak symmetry breaking, top quark physics is considered one of the least understood sectors of the Standard Model and represents a front line of our understanding of particle physics. Currently, the only direct measurements of top quark properties come from the CDF and D0 experiments observing p{bar p} collisions at the Tevatron. Top quark production at the Tevatron is almost exclusively by quark-antiquark annihilation, q{bar q} {yields} t{bar t} (85%), and gluon fusion, gg {yields} t{bar t} (15%), mediated by the strong force. The theoretical cross-section for this process is {sigma}{sub t{bar t}} = 6.7 {+-} 0.8 pb for m{sub t} = 175 GeV/c{sup 2}. Top quarks can also be produced at the Tevatron via q{bar b}{prime} {yields} tb and qg {yields} q{prime}tb through the weak interaction. The cross section for these processes is lower (3pb) and the signal is much more difficult to isolate as backgrounds are much higher. The top quark is predicted to decay almost exclusively into a W-boson and a bottom quark (t {yields} Wb). The total decay width t {yields} Wb is {Lambda} = 1.50 GeV. This corresponds to an incredibly short lifetime of 0.5 x 10{sup -24} seconds. This happens so quickly that hadronization and bound states do not take place, which leads to the interesting consequence that the top quark spin information is passed to the decay products.
Book Synopsis Forward-Backward Asymmetries in Top-Antitop Quark Production at the Tevatron by :
Download or read book Forward-Backward Asymmetries in Top-Antitop Quark Production at the Tevatron written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the combined results on inclusive forward-backward asymmetries in the production of top-antitop quark pairs and their decay leptons. The analysis is based on measurements by the CDF and D0 experiments at the Fermilab $p\bar{p}$ Tevatron collider using all the data collected at $\sqrt{s}$ = 1:96 TeV. The measured asymmetries are in agreement with standard model predictions.
Book Synopsis Supersymmetry and the Unification of Fundamental Interactions by : Deog Ki Hong
Download or read book Supersymmetry and the Unification of Fundamental Interactions written by Deog Ki Hong and published by AIP Conference Proceedings (Nu. This book was released on 2008-12-11 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt: This annual SUSY conference has become the world's largest international meeting devolted to new ideas in high energy physics. The main subject of the conference is theoretical and phenomenological aspects of supersymmetric theories, and dark matter and dark energy, and other comological connections. New, interesting results from various experimental groups are increasingly presented at the conference as well. With roughly 200 plenary and parallel presentations, SUSY08 will likely deliver energy and enthusiasm of both theorists and experimentalists who are searching the frontier of high energy physics.
Book Synopsis Measurement of Top Quark Polarization in Top-antitop Lepton+jets Final States at by :
Download or read book Measurement of Top Quark Polarization in Top-antitop Lepton+jets Final States at written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a measurement of the top quark polarization in the $t\overline{t}$ events produced in $p\overline{p}$ collisions at $\sqrt{s}=1.96$ TeV using data corresponding to 9.7 fb$^{-1}$ of integrated luminosity collected with the D0 detector at the Fermilab Tevatron Collider. The final states used in the measurement contain one lepton and at least three jets. The polarization is measured using the angular distribution of leptons along three different axes: the beam axis, the helicity axis, and the transverse axis normal to the $t\overline{t}$ production plane. This is the first measurement of top quark polarization at the Tevatron Collider in lepton+jets final states, and the first measurement of transverse polarization in $t\overline{t}$ production. The polarization along the beam axis is combined with the previous result in the dilepton final states by the D0 experiment. The observed distributions are consistent with the Standard Model of nearly no polarization and no indication for beyond Standard Model physics is observed. The measurement offers legacy result from unique Tevatron Collider data and provides more information about the top quark production and decays, about the properties of the heaviest elementary particle.
Book Synopsis Top Quark Pair Production Cross Section and Forward-Backward Asymmetry at the Tevatron by :
Download or read book Top Quark Pair Production Cross Section and Forward-Backward Asymmetry at the Tevatron written by and published by . This book was released on 2008 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present recent results on top quark pair production cross section and forward-backward asymmetry at the Tevatron. Three new cross section measurements from CDF and one new measurement from DO are presented that utilize the full dataset available. A new DO top cross section combination gives a ttbar production cross section of sigma ttbar = 7.83 + 0.46-0.45 (stat) + 0.64-0.53 (syst) +-0.48 (lumi). The new CDF cross section combination for ttbar production is found to be 7.0 +- 0.3 (stat) +- 0.4 (syst) +- 0.4 (lumi) pb giving a total uncertainty of 9%, very close to the that of the current best theoretical predictions. It is important to measure the top cross section in as many different channels as possible and investigate their compatibility. This is useful as new physics might show up differently in the different channels. Thus any significant discrepancy could be a sign of new physics. Three new measurements of the forward-backward asymmetry are also presented. The two CDF measurements unfold the observed asymmetry back to parton level in order to directly compare the values obtained with theoretical predictions. The DO measurement is not unfolded and therefore does not depend on the specific method used for unfolding.
Book Synopsis Measurement of the Cross Section of Top Quark Pairs Produced in Association with a Photon in Lepton + Jets Events at 8́(s by : Nabin Poudyal
Download or read book Measurement of the Cross Section of Top Quark Pairs Produced in Association with a Photon in Lepton + Jets Events at 8́(s written by Nabin Poudyal and published by . This book was released on 2021 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt: The inclusive production cross section of top quark pairs in association with a photon is measured in proton-proton collisions at the LHC with 13 TeV energy using the full RunII data collected by CMS in 2016, 2017, and 2018 with a total corresponding integrated luminosity of 137 fb 8́21 . The relative fraction of ttÎđ events normalized to inclusive tt production is measured. The cross section measurement provides important information about the electromagnetic coupling of the standard model top quark and is sensitive to physics beyond the standard model. The analysis is carried out in the in semileptonic decay channel with a well isolated high P T lepton (electron and muon), at least four jets out of which at least one must be b-tagged, and an isolated photon. Photons may be emitted from initial state radiation, top quarks, and decay products of top quarks. A simultaneous likelihood fit of control regions with the signal region is done to constraint the backgrounds and to extract the ttÎđ cross section. The measurement of the ratio of ttÎđ to tt is 0.02055 ℗ł 0.00099 (syst.) ℗ł 0.00099 (stat.) in the e + jets channel, 0.02156 ℗ł 0.00068 (syst.) ℗ł 0.00068 (stat.) in ℗æ + jets channel, and 0.02203 ℗ł 0.00064 (syst.) ℗ł 0.00064 (stat.) in the l + jets channel. The measured inclusive cross section is 3.81 ℗ł 0.15 (syst.) ℗ł 0.10 (stat.) pb in e + jets channel, 3.87 ℗ł 0.11 (syst.) ℗ł 0.07 (stat.) pb in ℗æ + jets channel, and 3.96 ℗ł 0.10 (syst.) ℗ł 0.06 (stat.) pb in l + jets channel for full RunII data. The results are in agreement with the standard model next to leading order prediction.
