Measurements of the Top Quark Pair Production Cross Section in Lepton + Jets Final States Using a Topological Multivariate Technique as Well as Lifetime B-Tagging in Proton - Anti-proton Collisions at S**(1/2)

Measurements of the Top Quark Pair Production Cross Section in Lepton + Jets Final States Using a Topological Multivariate Technique as Well as Lifetime B-Tagging in Proton - Anti-proton Collisions at S**(1/2) PDF Author:
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Languages : en
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Measurements of the Top Quark Pair Production Cross Section in Lepton + Jets Final States Using a Topological Multivariate Technique as Well as Lifetime B-Tagging InProton - Anti-proton Collisions at S**(1/2)

Measurements of the Top Quark Pair Production Cross Section in Lepton + Jets Final States Using a Topological Multivariate Technique as Well as Lifetime B-Tagging InProton - Anti-proton Collisions at S**(1/2) PDF Author: Tobias F. Golling
Publisher:
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Category :
Languages : en
Pages : 299

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Two alternative measurements of the t{bar t} production cross section at {radical}s = 1.96 TeV in proton-antiproton collisions in the lepton+jets channel are presented. The t{bar t} production cross section is extracted by combining the kinematic event information in a multivariate discriminant. The measurement yields {sigma}{sub p{bar p} {yields} t{bar t} + x} = 5.13{sub -1.57}{sup +1.76}(stat){sub -1.10}{sup +0.96}(syst) {+-} 0.33 (lumi) pb in the muon+jets channel, using 229.1 pb{sup -1}, and in the combination with the electron+jets channel 226.3 pb{sup -1} {sigma}{sub p{bar p} {yields} t{bar t} + x} = 6.60{sub -1.28}{sup +1.37}(stat){sub -1.11}{sup +1.25}(syst) {+-} 0.43 (lumi) pb. The second measurement presented reconstructs explicitly secondary vertices to d lifetime b-tagging. The measurement combines the muon+jets and the electron+jets channel, using 158.4 pb{sup -1} and 168.8 pb{sup -1}, respectively: {sigma}{sub p{bar p} {yields} t{bar t} + x} = 8.24{sub -1.25}{sup +1.34}(stat){sub -1.63}{sup +1.89}(syst) {+-} 0.54 (lumi) pb.

Measurements of the Top Quark Pair Production Cross Section in Lepton+jets Final States Using a Topological Multivariate Technique as Well as Lifetime B-tagging in Proton-antiproton Collisions at [root]

Measurements of the Top Quark Pair Production Cross Section in Lepton+jets Final States Using a Topological Multivariate Technique as Well as Lifetime B-tagging in Proton-antiproton Collisions at [root] PDF Author: Tobias Golling
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Measurements of the Top Quark Pair Production Cross Section in Lepton + Jets Final States Using a Topological Multivariate Technique as Well as Lifetime B-Tagging in Proton-Anti-proton Collisions at {u221A}s

Measurements of the Top Quark Pair Production Cross Section in Lepton + Jets Final States Using a Topological Multivariate Technique as Well as Lifetime B-Tagging in Proton-Anti-proton Collisions at {u221A}s PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 300

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Book Description
Two alternative measurements of the t¯t production cross section at √s = 1.96 TeV in proton-antiproton collisions in the lepton+jets channel are presented. The t¯t production cross section is extracted by combining the kinematic event information in a multivariate discriminant. The measurement yields ?p¯p → t¯t + x = 5.13-1.57+1.76(stat)-1.10+0.96(syst) ± 0.33 (lumi) pb in the muon+jets channel, using 229.1 pb-1, and in the combination with the electron+jets channel (226.3 pb-1) ?p¯p → t¯t + x = 6.60-1.28+1.37(stat)-1.11+1.25(syst) ± 0.43 (lumi) pb. The second measurement presented reconstructs explicitly secondary vertices to d lifetime b-tagging. The measurement combines the muon+jets and the electron+jets channel, using 158.4 pb-1 and 168.8 pb-1, respectively: ?p¯p → t¯t + x = 8.24-1.25+1.34(stat)-1.63+1.89(syst) ± 0.54 (lumi) pb.

Measurements of the Top Quark Pair Production Cross Section in Lepton+jets Final States Using a Topological Multivariate Technique as Well as Lifetime B-tagging in Proton-antiproton Collisions at √s

Measurements of the Top Quark Pair Production Cross Section in Lepton+jets Final States Using a Topological Multivariate Technique as Well as Lifetime B-tagging in Proton-antiproton Collisions at √s PDF Author: Tobias Golling
Publisher:
ISBN:
Category :
Languages : en
Pages : 291

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Top Quark Physics at Hadron Colliders

Top Quark Physics at Hadron Colliders PDF Author: Arnulf Quadt
Publisher: Springer Science & Business Media
ISBN: 3540710604
Category : Science
Languages : en
Pages : 166

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Book Description
This will be a required acquisition text for academic libraries. More than ten years after its discovery, still relatively little is known about the top quark, the heaviest known elementary particle. This extensive survey summarizes and reviews top-quark physics based on the precision measurements at the Fermilab Tevatron Collider, as well as examining in detail the sensitivity of these experiments to new physics. Finally, the author provides an overview of top quark physics at the Large Hadron Collider.

Measurement of the Single Top Quark Cross Section in the Lepton Plus Jets Final State in Proton-Antiproton Collisions at a Center of Mass Energy of 1.96 TeV Using the CDF II Detector

Measurement of the Single Top Quark Cross Section in the Lepton Plus Jets Final State in Proton-Antiproton Collisions at a Center of Mass Energy of 1.96 TeV Using the CDF II Detector PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 222

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Book Description
We present a measurement of the single top quark cross section in the lepton plus jets final state using an integrated luminosity corresponding to 7.5 fb-1 of p\bar p collision data collected by the Collider Detector at Fermilab. The single top candidate events are identified by the signature of a charged lepton, large missing transverse energy, and two or three jets with at least one of them identified as originating from a bottom quark. A new Monte Carlo generator POWHEG is used to model the single top quark production processes, which include s-channel, t-channel, and Wt-channel. A neural network multivariate method is exploited to discriminate the single top quark signal from the comparatively large backgrounds. We measure a single top production cross section of $3.04^{+0.57}_{-0.53} (\mathrm{stat.~+~syst.})$ pb assuming $m_{\rm top}=172.5$~GeV/$c^2$. In addition, we extract the CKM matrix element value $

Top Quark Pair Production Cross Section in the Lepton+jets Channel Using B-tagging at

Top Quark Pair Production Cross Section in the Lepton+jets Channel Using B-tagging at PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 184

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Book Description
The top quark pair production cross section measurement in the lepton+jets channel with b-tagging algorithm is described. About 900 pb−1 data collected by the D0 detector at the Fermilab Tevatron are used for this analysis. In this thesis, event selection, background estimation, and cross section calculation are discussed in detail. In addition, calibration of the Luminosity Monitor readout electronics and a new b-tagging algorithm, the SLTNN tagger, are also discussed in this thesis.

Measurement of the Top Quark Pair Production Cross Section and an In-situ B-tagging Efficiency Calibration with ATLAS in Pp Collisions at √s

Measurement of the Top Quark Pair Production Cross Section and an In-situ B-tagging Efficiency Calibration with ATLAS in Pp Collisions at √s PDF Author: Bin Guo
Publisher:
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Category :
Languages : en
Pages :

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Book Description
We present a measurement of the top anti-top quark (ttbar)production cross section in the dilepton final states from proton-proton collisions at a center of mass energy at 7 TeV at the LHC. A b-tagging algorithm based on tracks displaced from the event interaction vertex is applied to identify bottom quark jets from top quark decay and reject background events. Given the relatively pure sample of bottom quark jets in ttbar dilepton final states, a new technique to measure in-situ the b-tagging efficiency is introduced that uses the distribution of the number of observed b-tagged jets. We present results with data collected at the ATLAS detector in 2010 with an integrated luminosity of 35 pb-1. The measured ttbar cross section is 176 +22/-21 (stat.) ± 20 (syst.) ± 6 (lum.) pb in the dilepton channel. We will also discuss the future prospects of this measurement.

Measurement of the Cross Section of Top Quark Pairs Produced in Association with a Photon in Lepton + Jets Events at 8́(s

Measurement of the Cross Section of Top Quark Pairs Produced in Association with a Photon in Lepton + Jets Events at 8́(s PDF Author: Nabin Poudyal
Publisher:
ISBN:
Category : Physics
Languages : en
Pages : 259

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Book Description
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.