Determination of W Boson Helicity Fractions in Top Quark Decays in Pp Collisions at CDF RunII and Production of Endcap Modules for the ATLAS Silicon Tracker

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Total Pages : 165 pages
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Book Synopsis Determination of W Boson Helicity Fractions in Top Quark Decays in Pp Collisions at CDF RunII and Production of Endcap Modules for the ATLAS Silicon Tracker by : Shulamit Moed

Download or read book Determination of W Boson Helicity Fractions in Top Quark Decays in Pp Collisions at CDF RunII and Production of Endcap Modules for the ATLAS Silicon Tracker written by Shulamit Moed and published by . This book was released on 2007 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: La deuxième partie concerne la mesure des fractions d'hélicité longitudinale et droite du boson W dans la désintégration du quark top avec le détecteur CDF au Fermilab. Le résultat de cette mesure constitue un test très sensible du Modèle Standard des interactions électro-faibles. Pour la première fois les deux fractions d'hélicité ont été déterminées non seulement séparément mais aussi simultanément.

Determination of W Boson Helicity Fractions in Top Quark Decays in P$\bar{p}$ Collisions at CDF Run II and Production of Endcap Modules for the ATLAS Silicon Tracker

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Total Pages : 193 pages
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Book Synopsis Determination of W Boson Helicity Fractions in Top Quark Decays in P$\bar{p}$ Collisions at CDF Run II and Production of Endcap Modules for the ATLAS Silicon Tracker by :

Download or read book Determination of W Boson Helicity Fractions in Top Quark Decays in P$\bar{p}$ Collisions at CDF Run II and Production of Endcap Modules for the ATLAS Silicon Tracker written by and published by . This book was released on 2007 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: The thesis presented here includes two parts. The first part discusses the production of endcap modules for the ATLAS SemiConductor Tracker at the University of Geneva. The ATLAS experiment is one of the two multi-purpose experiments being built at the LHC at CERN. The University of Geneva invested extensive efforts to create an excellent and efficient module production site, in which 655 endcap outer modules were constructed. The complexity and extreme requirements for 10 years of LHC operation with a high resolution, high efficiency, low noise tracking system resulted in an extremely careful, time consuming production and quality assurance of every single module. At design luminosity about 1000 particles will pass through the tracking system each 25 ns. In addition to requiring fast tracking techniques, the high particle flux causes significant radiation damage. Therefore, modules have to be constructed within tight and accurate mechanical and electrical specification. A description of the ATLAS experiment and the ATLAS Semiconductor tracker is presented, followed by a detailed overview of the module production at the University of Geneva. My personal contribution to the endcap module production at the University of Geneva was taking part, together with other physicists, in selecting components to be assembled to a module, including hybrid reception tests, measuring the I-V curve of the sensors and the modules at different stages of the production, thermal cycling the modules and performing electrical readout tests as an initial quality assurance of the modules before they were shipped to CERN. An elaborated description of all of these activities is given in this thesis. At the beginning of the production period the author developed a statistics package which enabled us to monitor the rate and quality of the module production. This package was then used widely by the ATLAS SCT institutes that built endcap modules of any type, and kept being improved and updated. The production monitoring and summary using this package is shown in this thesis. The second part of the thesis reports a measurement of the fraction of longitudinal and right-handed helicity states of W bosons in top quark decays. This measurement was done using 955 pb-1 of data collected with the CDF detector at the TEvatron, where protons and anti-protons are collided with a center-of-mass energy of 1.96 TeV. the helicity fraction measurements take advantage of the fact that the angular distribution of the W boson decay products depends on the helicity state of the W which they originate from. They analyze t$\bar{t}$ events in the 'lepton+jets' channel and look at the leptonic side of decay. They construct templates for the distribution of cos?*, the angle between the charged lepton and the W flight direction in the rest frame of the top quark. Using Monte Carlo techniques, they construct probability distributions ('templates') for cos?* in the case of left-handed, longitudinal and right-handed Ws and a template for the background model. They extract the W helicity fractions using an unbinned likelihood fitter based on the information of these templates. The Standard Model predicts the W helicity fractions to be about 70% longitudinal and 30% left-handed, while the fraction of right-handed W bosons in top decays is highly suppressed and vanishes when neglecting the mass of the b quark.

Determination of W Boson Helicity Fractions in Top Quark Decays in P Anti-p Collisions at CDF Run II and Production of Endcap Modules for the ATLAS Silicon Tracker

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Total Pages : 193 pages
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Book Synopsis Determination of W Boson Helicity Fractions in Top Quark Decays in P Anti-p Collisions at CDF Run II and Production of Endcap Modules for the ATLAS Silicon Tracker by :

Download or read book Determination of W Boson Helicity Fractions in Top Quark Decays in P Anti-p Collisions at CDF Run II and Production of Endcap Modules for the ATLAS Silicon Tracker written by and published by . This book was released on 2007 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: The thesis presented here includes two parts. The first part discusses the production of endcap modules for the ATLAS SemiConductor Tracker at the University of Geneva. The ATLAS experiment is one of the two multi-purpose experiments being built at the LHC at CERN. The University of Geneva invested extensive efforts to create an excellent and efficient module production site, in which 655 endcap outer modules were constructed. The complexity and extreme requirements for 10 years of LHC operation with a high resolution, high efficiency, low noise tracking system resulted in an extremely careful, time consuming production and quality assurance of every single module. At design luminosity about 1000 particles will pass through the tracking system each 25 ns. In addition to requiring fast tracking techniques, the high particle flux causes significant radiation damage. Therefore, modules have to be constructed within tight and accurate mechanical and electrical specification. A description of the ATLAS experiment and the ATLAS Semiconductor tracker is presented, followed by a detailed overview of the module production at the University of Geneva. My personal contribution to the endcap module production at the University of Geneva was taking part, together with other physicists, in selecting components to be assembled to a module, including hybrid reception tests, measuring the I-V curve of the sensors and the modules at different stages of the production, thermal cycling the modules and performing electrical readout tests as an initial quality assurance of the modules before they were shipped to CERN. An elaborated description of all of these activities is given in this thesis. At the beginning of the production period the author developed a statistics package which enabled us to monitor the rate and quality of the module production. This package was then used widely by the ATLAS SCT institutes that built endcap modules of any type, and kept being improved and updated. The production monitoring and summary using this package is shown in this thesis. The second part of the thesis reports a measurement of the fraction of longitudinal and right-handed helicity states of W bosons in top quark decays. This measurement was done using 955 pb−1 of data collected with the CDF detector at the TEvatron, where protons and anti-protons are collided with a center-of-mass energy of 1.96 TeV. the helicity fraction measurements take advantage of the fact that the angular distribution of the W boson decay products depends on the helicity state of the W which they originate from. They analyze t{bar t} events in the 'lepton+jets' channel and look at the leptonic side of decay. They construct templates for the distribution of cos[theta]*, the angle between the charged lepton and the W flight direction in the rest frame of the top quark. Using Monte Carlo techniques, they construct probability distributions ('templates') for cos[theta]* in the case of left-handed, longitudinal and right-handed Ws and a template for the background model. They extract the W helicity fractions using an unbinned likelihood fitter based on the information of these templates. The Standard Model predicts the W helicity fractions to be about 70% longitudinal and 30% left-handed, while the fraction of right-handed W bosons in top decays is highly suppressed and vanishes when neglecting the mass of the b quark.

Combination of CDF and D0 Measurements of the $W$ Boson Helicity in Top Quark Decays

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ISBN 13 :
Total Pages : 11 pages
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Book Synopsis Combination of CDF and D0 Measurements of the $W$ Boson Helicity in Top Quark Decays by :

Download or read book Combination of CDF and D0 Measurements of the $W$ Boson Helicity in Top Quark Decays written by and published by . This book was released on 2012 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report the combination of recent measurements of the helicity of the W boson from top quark decay by the CDF and D0 collaborations, based on data samples corresponding to integrated luminosities of 2.7-5.4 fb−1 of p{bar p} collisions collected during Run II of the Fermilab Tevatron Collider. Combining measurements that simultaneously determine the fractions of W bosons with longitudinal (f0) and right-handed (f+) helicities, we find f0 = 0.722 ± 0.081 [± 0.062 (stat.) ± 0.052 (syst.)] and f+ = -0.033 ± 0.046 [± 0.034 (stat.) ± 0.031 (syst.)]. Combining measurements where one of the helicity fractions is fixed to the value expected in the standard model, we find f0 = 0.682 ± 0.057 [± 0.035 (stat.) ± 0.046 (syst.)] and f+ =?0.015 ± 0.035 [± 0.018 (stat.) ± 0.030 (syst.)]. The results are consistent with standard model expectations.

Measurement of the W-boson Helicity Fractions in Top-quark Decays at CDF.

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ISBN 13 :
Total Pages : 4 pages
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Book Synopsis Measurement of the W-boson Helicity Fractions in Top-quark Decays at CDF. by :

Download or read book Measurement of the W-boson Helicity Fractions in Top-quark Decays at CDF. written by and published by . This book was released on 2007 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the fractions F0 and F+ of longitudinally polarized and right-handed W bosons in top-quark decays using data collected with the CDF II detector. The data set used in the analysis corresponds to an integrated luminosity of approximately 955 pb−1. We select t{bar t} candidate events with one lepton, at least four jets, and missing transverse energy. Our helicity measurement uses the decay angle [theta]*, which is defined as the angle between the momentum of the charged lepton in the W boson rest-frame and the W momentum in the top-quark rest-frame. The cos[theta]* distribution in the data is determined by full kinematic reconstruction of the t{bar t} candidates. We find F0= 0.59 ± 0.12(stat){sup +0.07}{sub -0.06}(syst) and F+=-0.03 ± 0.06(stat){sup +0.04}{sub -0.03}(syst), which is consistent with the standard model prediction. We set an upper limit on the fraction of right-handed W bosons of F+ ≤ 0.10 at the 95% confidence level.

Measurement of the W Boson Helicity in Top-antitop Quark Events with the CDF II Experiment

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ISBN 13 :
Total Pages : 102 pages
Book Rating : 4.:/5 (316 download)

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Book Synopsis Measurement of the W Boson Helicity in Top-antitop Quark Events with the CDF II Experiment by : Thorsten Chwalek

Download or read book Measurement of the W Boson Helicity in Top-antitop Quark Events with the CDF II Experiment written by Thorsten Chwalek and published by . This book was released on 2006 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1995 the top quark was discovered at the Tevatron proton-antiproton collider at Fermilab by the CDF and D0 collaborations [1, 2]. It is the most massive known elementary particle and its mass is currently measured with a precision of about 1.3% [3, 4]. However, the measurements of several other top quark properties are still statistically limited, so the question remains whether the Standard Model of elementary particle physics successfully predicts these properties. This thesis addresses one interesting aspect of top quark decay, the helicity of the produced W boson. Until the start of the Large Hadron Collider (LHC) at CERN, the Tevatron with a center-of-mass energy of {radical}s = 1.96 TeV is the only collider, where top quarks can be produced. In the Standard Model the top quark decays predominantly into a W boson and a b quark, with a branching ratio close to 100%. The V-A structure of the weak interaction of the Standard Model predicts that the W{sup +} bosons from the top quark decay t {yields} W{sup +}b are dominantly either longitudinally polarized or left handed, while right handed W bosons are heavily suppressed and even forbidden in the limit of a massless b quark. Under the assumption of a massless b quark, for a top quark mass of 173 GeV/c{sup 2} the Standard Model predicts the fraction F0 of longitudinally polarized W bosons to be 0.7 and 0.3 for the fraction F{_} of left handed W bosons, while the fraction F{sub +} of right handed W bosons is predicted to be zero. Since next-to-leading order corrections change these fractions only slightly, a significant deviation from the predicted value for F{sub 0} or a nonzero value for F{sub +} could indicate new physics. Left-right symmetric models [5], for example, lead to a significant right handed fraction of W bosons in top decays. Such a right handed component (V+A coupling) would lead to a smaller left handed fraction, while F{sub 0} would remain unchanged. Since the decay rate to longitudinal W bosons depends on the Yukawa coupling of the top quarks, the measurement of F{sub 0} is sensitive to the mechanism of electroweak symmetry breaking. Alternative models can lead to an altered F{sub 0} fraction. In this analysis the W helicity fractions are measured in a selected sample rich in t{bar B} events where one lepton, at least four jets, and missing transverse energy are required. All kinematic quantities describing the t{bar t} decay are determined. As a sensitive observable, we use the cosine of the decay angle {theta}*, which is defined as the angle between the momentum of the charged lepton in the W boson rest frame and the W boson momentum in the top quark rest frame. The data used in this analysis were taken with the Collider Detector at Fermilab (CDF II) in the years 2002-2006 and correspond to an integrated luminosity of about 955 pb{sup -1}. Previous CDF measurements of the W boson helicity fractions in top quark decays used either the square of the invariant mass of the charged lepton and the b quark jet, M{sub {ell}b}{sup 2}, or the lepton p{sub T} distribution as a discriminant. The D0 collaboration used a matrix-element method to extract a value of F{sub 0}; in a second analysis the reconstructed distribution of cos {theta}* was utilized to measure F{sub +}. CDF gives the latest value of F{sub 0} = 0.74{sub -0.34}{sup +0.22}, while D measured F{sub 0} = 0.56 {+-} 0.31. The CDF collaboration also gives the current upper limit of F{sub +}

Measurement of the W Boson Helicity Fractions in the Decays of Top Quark Pairs to Lepton+jets Final States Produced in Pp Collisions at Sqrt(s)

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Book Synopsis Measurement of the W Boson Helicity Fractions in the Decays of Top Quark Pairs to Lepton+jets Final States Produced in Pp Collisions at Sqrt(s) by :

Download or read book Measurement of the W Boson Helicity Fractions in the Decays of Top Quark Pairs to Lepton+jets Final States Produced in Pp 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: The W boson helicity fractions from top quark decays in t-tbar events are measured using data from proton-proton collisions at a centre-of-mass energy of 8 TeV. The data were collected in 2012 with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.8 inverse-femtobarns. Events are reconstructed with either one muon or one electron, along with four jets in the final state, with two of the jets being identified as originating from b quarks. The measured helicity fractions from both channels are combined, yielding F[0] = 0.681 +/- 0.012 (stat) +/- 0.023 (syst), F[L] = 0.323 +/- 0.008 (stat) +/- 0.014 (syst), and F[R] = -0.004 +/- 0.005 (stat) +/- 0.014 (syst) for the longitudinal, left-, and right-handed components of the helicity, respectively. These measurements of the W boson helicity fractions are the most accurate to date and they agree with the predictions from the standard model.

Measurement of W Boson Helicity Fractions in T Anti-t Decays at DZero and CDF.

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Book Synopsis Measurement of W Boson Helicity Fractions in T Anti-t Decays at DZero and CDF. by :

Download or read book Measurement of W Boson Helicity Fractions in T Anti-t Decays at DZero and CDF. written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The properties of the W boson can be probed in top quark decays t --> bW. The CDF and DZero collaborations have released updated measurements of the W boson helicity fractions f0, f+ and f. The analysis techniques and updated measurements are discussed. This paper summarizes the talk given at the DIS2008 conference.

Measurement of the W Boson Helicity in Events with a Single Reconstructed Top Quark in Pp Collisions at $ \sqrt{s}

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ISBN 13 :
Total Pages : 33 pages
Book Rating : 4.:/5 (925 download)

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Book Synopsis Measurement of the W Boson Helicity in Events with a Single Reconstructed Top Quark in Pp Collisions at $ \sqrt{s} by :

Download or read book Measurement of the W Boson Helicity in Events with a Single Reconstructed Top Quark in Pp Collisions at $ \sqrt{s} written by and published by . This book was released on 2015 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the W boson helicity is presented, where the W boson originates from the decay of a top quark produced in pp collisions. The event selection, optimized for reconstructing a single top quark in the final state, requires exactly one isolated lepton (muon or electron) and exactly two jets, one of which is likely to originate from the hadronization of a bottom quark. The analysis is performed using data recorded at a center-of-mass energy of 8 TeV with the CMS detector at the CERN LHC in 2012. The data sample corresponds to an integrated luminosity of 19.7 fb$^{-1}$. The measured helicity fractions are F$_{L}$ = 0.298 " 0.028 (stat) " 0.032(syst), F$_{0}$ = 0.720 " 0.039 (stat) " 0.037(syst), and F$_{R}$ = -0.018 " 0.019 (stat) " 0.011(syst). These results are used to set limits on the real part of the tWb anomalous couplings, g$_{L}$ and g$_{R}$.

Measurement of the Helicity Fractions of W Bosons from Top Quark Decays Using Fully Reconstructed T Anti-t Events with CDF II.

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ISBN 13 :
Total Pages : 11 pages
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Book Synopsis Measurement of the Helicity Fractions of W Bosons from Top Quark Decays Using Fully Reconstructed T Anti-t Events with CDF II. by :

Download or read book Measurement of the Helicity Fractions of W Bosons from Top Quark Decays Using Fully Reconstructed T Anti-t Events with CDF II. written by and published by . This book was released on 2006 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present a measurement of the fractions F0 and F+ of longitudinally polarized and right-handed W bosons in top quark decays using data collected with the CDF II detector. The data set used in the analysis corresponds to an integrated luminosity of approximately 318 pb−1. They select t{bar t} candidate events with one lepton, at least four jets, and missing transverse energy. The helicity measurement uses the decay angle [theta]*, which is defined as the angle between the momentum of the charged lepton in the W boson rest frame and the W momentum in the top quark rest frame. The cos [theta]* distribution in the data is determined by full kinematic reconstruction of the t{bar t} candidates. They find F0 = 0.85{sub -0.22}{sup +0.15}(stat)±0.06(syst) and F+ = 0.05{sub -0.05}{sup +0.11}(stat) ± 0.03(syst), which is consistent with the standard model prediction. They set an upper limit on the fraction of right-handed W bosons of F+

Measurement of the W-boson Helicity in Top-quark Decays from $t\bar{t}$ Production in Lepton+jets Events in Pp Collisions at $\sqrt{s}

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ISBN 13 :
Total Pages : 45 pages
Book Rating : 4.:/5 (16 download)

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Book Synopsis Measurement of the W-boson Helicity in Top-quark Decays from $t\bar{t}$ Production in Lepton+jets Events in Pp Collisions at $\sqrt{s} by :

Download or read book Measurement of the W-boson Helicity in Top-quark Decays from $t\bar{t}$ Production in Lepton+jets Events in Pp Collisions at $\sqrt{s} written by and published by . This book was released on 2013 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Measurement of W-Boson Helicity Fractions in Top-Quark Decays Using Costheta*

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ISBN 13 :
Total Pages : 17 pages
Book Rating : 4.:/5 (727 download)

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Book Synopsis Measurement of W-Boson Helicity Fractions in Top-Quark Decays Using Costheta* by :

Download or read book Measurement of W-Boson Helicity Fractions in Top-Quark Decays Using Costheta* written by and published by . This book was released on 2008 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Measurement of the W Boson Helicity Fractions in Top/anit-top Events at 8 TeV in the Lepton + Jets Channel with the ATLAS Detector

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ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (984 download)

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Book Synopsis Measurement of the W Boson Helicity Fractions in Top/anit-top Events at 8 TeV in the Lepton + Jets Channel with the ATLAS Detector by : Mohammad Jawad Kareem

Download or read book Measurement of the W Boson Helicity Fractions in Top/anit-top Events at 8 TeV in the Lepton + Jets Channel with the ATLAS Detector written by Mohammad Jawad Kareem and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Precise measurements of the properties of the top quark allow for testing the Standard Model (SM) and can be used to constrain new physics models. The top quark is predicted in the SM to decay almost exclusively to a W boson and b-quark. Thus, studying the Wtb vertex structure at high precision and in detail is motivated. This thesis presents a measurement of the W boson helicity fractions in top quark decays with top/anit-top events in the lepton + jets final state using proton-proton collisions at a centre-of-mass energy of 8 TeV recorded in 2012 with the ATLAS detector at the LHC. The da...

Measurement of the Helicity of W Bosons in Top Quark Decays

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ISBN 13 :
Total Pages : 204 pages
Book Rating : 4.3/5 (91 download)

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Book Synopsis Measurement of the Helicity of W Bosons in Top Quark Decays by : David J. Winn

Download or read book Measurement of the Helicity of W Bosons in Top Quark Decays written by David J. Winn and published by . This book was released on 2000 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Measurement of the W Boson Helicity in Top Quark Decays Using 5.4 Fb$^{\boldsymbol{-1}}$ of $\boldsymbol{p\bar{p}}$ Collision Data

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Book Synopsis Measurement of the W Boson Helicity in Top Quark Decays Using 5.4 Fb$^{\boldsymbol{-1}}$ of $\boldsymbol{p\bar{p}}$ Collision Data by :

Download or read book Measurement of the W Boson Helicity in Top Quark Decays Using 5.4 Fb$^{\boldsymbol{-1}}$ of $\boldsymbol{p\bar{p}}$ Collision Data 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 helicity of the W boson produced in top quark decays using t{bar t} decays in the l+jets and dilepton final states selected from a sample of 5.4 fb−1 of collisions recorded using the D0 detector at the Fermilab Tevatron p{bar p} collider. We measure the fractions of longitudinal and right-handed W bosons to be f0 = 0.669 ± 0.102 [±0.078 (stat.) ± 0.065 (syst.)] and f+ = 0.023 ± 0.053 [±0.041 (stat.)±0.034 (syst.)], respectively. This result is consistent at the 98% level with the standard model. A measurement with f0 fixed to the value from the standard model yields f+ = 0.010 ± 0.037 [±0.022 (stat.) ± 0.030 (syst.)].

A Measurement of the Helicity of W Bosons Produced in Top-quark Decays

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ISBN 13 :
Total Pages : 254 pages
Book Rating : 4.3/5 (91 download)

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Book Synopsis A Measurement of the Helicity of W Bosons Produced in Top-quark Decays by : Nathan J. Goldschmidt

Download or read book A Measurement of the Helicity of W Bosons Produced in Top-quark Decays written by Nathan J. Goldschmidt and published by . This book was released on 2005 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Measurement of the W Boson Helicity in Top Quark Decays

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ISBN 13 :
Total Pages : 172 pages
Book Rating : 4.:/5 (873 download)

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Book Synopsis Measurement of the W Boson Helicity in Top Quark Decays by :

Download or read book Measurement of the W Boson Helicity in Top Quark Decays written by and published by . This book was released on 2007 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the fraction, f+, of right-handed W bosons produced in top quark decays is presented. This analysis is based on a sample corresponding to an integrated luminosity of 370 pb−1, collected by the D0 detector at the Fermilab Tevatron p{bar p} Collider at √s = 1.96 TeV. The helicity angle, [theta]*, is reconstructed for each lepton. f+ is determined by comparing the cos [theta]* distribution from the data with that for the expected background and signal for various values of f+. The fraction of longitudinal W bosons, f°, is assumed to be 0.7 as predicted by the standard model. This yields f+ = 0.109 ± 0.094 (stat) ± 0.063 (syst), consistent with the standard model prediction of f+ = 3.6x 10−4. The possibility that both f+ and f° stray from standard model values is also investigated. In this case cos [theta]* distributions for each possible W helicity state, along with the backgrounds, are fit to the cos [theta]* distribution for the data. The best fit values are f+ = 0.82 ± 0.30(stat) and f° = -0.58 ± 0.50(stat).