Haut PDF Contributions to a first measurement of the W-boson mass in the electron channel with the ATLAS detector

Contributions to a first measurement of the W-boson mass in the electron channel with the ATLAS detector

Contributions to a first measurement of the W-boson mass in the electron channel with the ATLAS detector

Abstract In this document, I present my contributions to a first measurement of the W-mass in the LHC using 4.7 fb −1 of 7 TeV data, taken in 2011. I focus on the electron decay channel, W → eν. In the first part, I discuss a study regarding the performance of the electromagnetic calorimeter of the ATLAS detector, presenting a novel method to correct the lateral profiles of electron energy deposit, along with various studies of the different Geant4 physics lists versions. In the second part, I introduce the global methodology for the W-mass measurement used in ATLAS, and discuss my contributions in details. I show in a first step the assessment of uncertainties coming from the parton shower modeling in Pythia8, and the optimization of the p ` T fitting range in order to reduce the systematic uncertainty. In a second step, I present an elaborate data-driven method for the estimation of the multijet background in the W → eν channel, as well as the corresponding results in terms of event yields and fractions with respect to the signal data. The corresponding uncertainties on the W-mass are also shown. Finally, I show the state of the art of the analysis, by gathering the full breakdown of the uncertainties, in bins of pseudorapidity and average pileup.
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Measurement of $W^+W^-$ production in association with one jet in proton--proton collisions at $\sqrt{s} =8$ TeV with the ATLAS detector

Measurement of $W^+W^-$ production in association with one jet in proton--proton collisions at $\sqrt{s} =8$ TeV with the ATLAS detector

contributions from misidentified leptons produced in multijet and W +jets events. Apart from the require- ments on the jets and ∆φ(E miss T , p miss T ), this event selection is identical to the one employed in Ref. [ 14 ]. 4 Determination of backgrounds The experimental signature of exactly one electron and one muon with opposite electric charge, and missing transverse momentum can be produced by a variety of SM processes which are treated as back- grounds. Top quarks decay almost exclusively to a b-quark and a W boson. This makes t¯t and single top-quark production the dominant background to WW production, in particular for events with jets in the final state. The background yield from top-quark production is determined using a method proposed in Ref. [ 51 ]. The event yield is extrapolated from a control sample enriched in events from top-quark production. It is defined by the nominal selection requirements but must contain exactly one identified b-jet with p T > 25 GeV and within |η| < 2.5, instead of requiring the absence of identified b-jets. The distribution of the transverse momentum of the b-jet in the control sample is shown in Figure 1 (a). The data is used to constrain the large experimental and theoretical uncertainties shown by the error bands. The factor to extrapolate from this control sample to the signal sample is determined as the ratio of jets passing or failing the b-jet requirement in additional control samples, defined by the presence of two jets, at least one of which passes passes the b-tag requirement. Systematic effects resulting from the choice of the control sample are corrected for by an additional factor estimated from simulated event samples. The correction introduces experimental systematic uncertainties of ±3.1%, mainly from the uncertainty in the jet energy scale. Theoretical uncertainties are found to amount to ±2.5% and are dominated by differ- ences in simulated tt event samples produced with Powheg and MC@NLO, and uncertainties in the Wt production cross section. Statistical uncertainties from the limited size of the control samples in data and simulation introduce an uncertainty of ±3.5%, resulting in an overall precision in the estimated top-quark background yield of ±5.2%.
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Measurement of the Z boson differential cross-section in transverse momentum in the electron-positron channel with the ATLAS detector at LHC.

Measurement of the Z boson differential cross-section in transverse momentum in the electron-positron channel with the ATLAS detector at LHC.

In the next section we detail the steps mentioned above, and explain the corrections done on the templates before the fitting procedure is performed. QCD control sample The control sample is built using 2011 collision data, with the selection cuts summarized in table 5.4 . We use inclusive D3PD’s instead of skimmed ones, in order to have background events available for the selection. The trigger requirement is modified in order to require loose elec- tromagnetic clusters (instead of online reconstructed electrons), and the electron identification is inverted, asking the electrons to pass the loose identification but not the medium one (see section 3.2.3 ). This cut inversion allows to select mostly background and fake electrons. The opposite charge requirement is removed, keeping all events and dividing the selected sample in two, according to the relative charge of the two electrons in the event, opposite sign (OS) and same sign (SS) samples.
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Search for a fermiophobic Higgs boson in the diphoton decay channel with the ATLAS detector

Search for a fermiophobic Higgs boson in the diphoton decay channel with the ATLAS detector

based direction measurement. The total relative uncer- tainty on the diphoton invariant mass resolution is thus ±14%. Systematic uncertainties on the background mod- elling arise from a possible deviation of the background mass distribution from the assumed exponential shape. This uncertainty is evaluated as the number of events that could be mistakenly attributed to the signal. It is estimated from the adequacy of the chosen background model’s description of the mass distribution predicted by ResBos [32]. The residuals of the fit of the back- ground model to the ResBos diphoton mass distribution are integrated over a sliding mass window of 4 GeV, the approximate FWHM of the expected signal. The largest deviations were found at small invariant masses and these uncertainties are then applied over the whole mass range. The resulting uncertainties range from ±0.1 to ±7.9 events in the individual analysis categories, where the magnitude of these uncertainties is roughly propor- tional to the number of background events in each cate- gory. These absolute uncertainties do not scale with the signal strength in the final likelihood fit. For a fermio- phobic Higgs boson with m H = 120 GeV the back-
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Measurement of $W^{\pm}W^{\pm}$ vector-boson scattering and limits on anomalous quartic gauge couplings with the ATLAS detector

Measurement of $W^{\pm}W^{\pm}$ vector-boson scattering and limits on anomalous quartic gauge couplings with the ATLAS detector

9 Extraction of anomalous quartic gauge couplings VBS events receive contributions from quartic gauge boson interactions and thus can be used to search for aQGCs. In general, the e ffective Lagrangian described in Section 1 does not ensure unitarity. The Higgs boson in the SM ensures unitarity of the SM VBS process, which is destroyed if anomalous couplings or additional resonances are added. A unitarization scheme has to be applied in order to avoid non-physical predictions. In the case of VBS with aQGC, the unitarization significantly impacts the di fferential and total cross-sections. The K-matrix unitarization scheme [ 17 ] is applied in this analysis where the elastic scattering eigen-amplitude A(s) is projected on the Argand circle A(s) → ˆ A(s) such that | ˆ A(s) − i/2| = 1/2. This condition is derived from the optical theorem and ensures that the projected scattering amplitude meets the unitarity condition exactly. As a result, the cross-section saturates at the maximum value allowed by unitarity. The whizard [ 75 ] event generator is used to calculate cross-sections and generate events with aQGCs at LO in QCD. The CTEQ6L1 PDF set is used. All samples use the parameterization in terms of α 4 and α 5 . The invariant mass of the system of two charged leptons and two neutrinos from the decay of the two W bosons, m ``νν , is used as the renormalization and factorization scales, µ R = µ F = m ``νν . The events are interfaced to pythia 8 for modeling the parton shower, QED final-state radiation, decays of τ leptons, and the underlying event.
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Measurement of the Z to tau tau Cross Section with the ATLAS Detector

Measurement of the Z to tau tau Cross Section with the ATLAS Detector

I. INTRODUCTION Tau leptons play a significant role in the search for new physics phenomena at CERN’s Large Hadron Collider (LHC). Hence decays of Standard Model gauge bosons to τ leptons, W → τν and Z → ττ, are important back- ground processes in such searches and their production cross sections need to be measured precisely. Studies of Z → ττ processes at the LHC center-of-mass energies are also interesting in their own right, complementing the measurements of the Z boson through the electron and muon decay modes. Finally, measuring the cross section of a well-known Standard Model process involv- ing τ leptons is highly important for the commissioning and validation of τ identification techniques, which will be crucial for fully exploiting the ATLAS experiment’s potential in searches for new physics involving τ leptons. This paper describes the measurement of the Z → ττ cross section, using four different final states and an inte- grated luminosity of 36 pb −1 , in pp collisions at a center- of-mass energy of √ s = 7 TeV recorded with the ATLAS detector [1] at the LHC. Two of the considered final states are the semileptonic modes Z → ττ → µ + hadrons + 3ν (τ µ τ h ) and Z → ττ → e + hadrons + 3ν (τ e τ h ) with branching fractions (22.50 ± 0.09)% and (23.13 ± 0.09)% respectively [2]. The remaining two final states are the leptonic modes Z → ττ → eµ + 4ν (τ e τ µ ) and Z → ττ → µµ + 4ν (τ µ τ µ ) with branching fractions (6.20 ± 0.02)% and (3.01 ± 0.01)%, respectively [2]. Due to the large expected multijet background contamination, the τ h τ h and τ e τ e final states are not considered in this publication.
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Heavy Higgs Boson Search in the Four Lepton Decay Channel with the ATLAS Detector

Heavy Higgs Boson Search in the Four Lepton Decay Channel with the ATLAS Detector

Figure 5.5: The reconstructed qq ! ZZ mass spectrum. Green line corresponds to the m 4` variable without Z mass constraint, blue - single Z mass constraint, red - double Z mass constraint. 5.4 Background The main background is coming from the Standard Model production of Z boson pair with further decay to four leptons. This process has exactly the same final state topology as the signal (further called irreducible), namely four well isolated leptons are produced. Therefore, it is hard to construct a signal region (SR) that is not contaminated by this background, but fortunately this process can be simulated with reasonable accuracy. This final state can be produced in two reactions: qq ! ZZ and gg ! ZZ (Figure 5.6), while the production rate of the first one is about ten times higher than the second. Since these two production modes involved quite di↵erent physics, they are simulated separately with POWHEG and SHERPA accordingly. Quark-antiquark annihilation has up to NNLO QCD and NLO EW corrections applied [117], while the gluon-gluon channel is known only at leading order precision and has conservative 60% uncertainty due to higher order corrections.
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Measurement of Higgs boson production in the diphoton decay channel in $pp$ collisions at center-of-mass energies of 7 and 8 TeV with the ATLAS detector

Measurement of Higgs boson production in the diphoton decay channel in $pp$ collisions at center-of-mass energies of 7 and 8 TeV with the ATLAS detector

Measurement of Higgs boson production in the diphoton decay channel in pp collisions at center-of-mass energies of 7 and 8 TeV with the ATLAS detector (Dated: September 10, 2014) A measurement of the production processes of the recently discovered Higgs boson is performed in the two-photon final state using 4.5 fb −1 of proton–proton collisions data at √ s = 7 TeV and 20.3 fb −1 at √ s = 8 TeV collected by the ATLAS detector at the Large Hadron Collider. The number of observed Higgs boson decays to diphotons divided by the corresponding Standard Model prediction, called the signal strength, is found to be µ = 1.17 ± 0.27 at the value of the Higgs boson mass measured by ATLAS, m H = 125.4 GeV. The analysis is optimized to measure the signal strengths for individual Higgs boson production processes at this value of m H . They are found to be µ ggF = 1.32 ± 0.38, µ VBF = 0.8 ± 0.7, µ W H = 1.0 ± 1.6, µ ZH = 0.1 +3.7 −0.1 , and µ t¯ tH = 1.6 +2.7 −1.8 , for Higgs boson production through gluon fusion, vector-boson fusion, and in association with a W or Z boson or a top-quark pair, respectively. Compared with the previously published ATLAS analysis, the results reported here also benefit from a new energy calibration procedure for photons and the subsequent reduction of the systematic uncertainty on the diphoton mass resolution. No significant deviations from the predictions of the Standard Model are found.
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Precision measurement and interpretation of inclusive $W^+$, $W^-$ and $Z/\gamma^*$ production cross sections with the ATLAS detector

Precision measurement and interpretation of inclusive $W^+$, $W^-$ and $Z/\gamma^*$ production cross sections with the ATLAS detector

diboson production. The sum of electroweak and top-quark backgrounds ranges from 4.5% to 9.6% in the Wchannel and from 4.0% to 7.0% in the W + channel. In contrast to W → τν background, the other electroweak and top-quark background yields are of similar absolute size in W + and W − events. The multijet background in the W → µν channel originates primarily from heavy-quark decays, with smaller contributions from pion and kaon decays in flight and fake muons from hadrons that punch through the calorimeter. Given the uncertainty in the dijet cross-section prediction and the di fficulty of properly simulating non-prompt muons, the multijet background is derived from data. The number of background events is determined from a binned maximum-likelihood template fit to the E miss T distribution, as shown in the left panel of Figure 2 . The fit is used to determine the normalization of two components, one for the signal and electroweak plus top-quark backgrounds, taken from simulation, and a second for the multijet background, derived from data. No prior knowledge of the normalization of the two compon- ents is assumed. The multijet template is derived from a control sample defined by reversing the isolation requirement imposed to select the signal and without applying any requirement on E miss T . The fits are done separately for W + and W − events and in each η region of the differential cross-section measurement. This analysis yields a fraction of multijet background events between 2.7% in the most central pseu- dorapidity bin and 1.3% in the most forward bin of the measurement for the W + channel and between 3.5% and 2.6% for the Wchannel, respectively. The systematic uncertainty, dominated by the uncer- tainty in the E T miss modelling for signal events in simulation, is estimated to be about 0.4–0.8% relative to the number of background events. While this background is determined separately for W + and W − samples, the resulting background yields are found to be compatible between both charges within the statistical uncertainty. As in the electron channel, the multijet background was also determined with an alternative method following Ref. [ 7 ], which gives an estimate well within the systematic uncertainty assigned to the baseline determination described above.
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Measurement of the cross-section for W boson production in association with b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

Measurement of the cross-section for W boson production in association with b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

be on the efficiency plateau for the respective triggers. The selection efficiency of electrons and muons in simulated events, as well as their energy and momentum scale and resolution, are adjusted to reproduce those observed in Z → `` events in data [ 29 – 31 ]. In order to reduce the large background from multijet production, lepton candidates are required to be isolated from neighbouring tracks within ∆R = 0.4 of their direction, as well as from other calorimeter energy depositions, corrected for pile-up contributions, within ∆R = 0.2. In the muon case, the sum of transverse momenta of neighbouring tracks must be less than 2 GeV, while the sum of the calorimeter transverse energies must be less than 1 GeV. In the electron case, these requirements range between 1.35 GeV and 3.15 GeV depending on p T and η in order to yield a constant efficiency across momentum ranges and detector regions. Additionally, leptons are required to be consistent with originating from the PV. Their longitudinal impact parameter (|z 0 |) with respect to the PV must be smaller
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Measurement of $W^\pm $ boson production in Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}} = 5.02~\text {Te}\text {V}$ with the ATLAS detector

Measurement of $W^\pm $ boson production in Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}} = 5.02~\text {Te}\text {V}$ with the ATLAS detector

the electron channel, a significant difference in the evolution of the C W correction factor can be noticed between the central (|η| < 1.37) and forward pseudorapidities (1.52 < |η| < 2.47). That behaviour can be attributed to the electron reconstruction efficiency, which increases in the forward region as a function of centrality from ∼75% to ∼95% almost compensating for other effects, while in the barrel region it changes from ∼90% to ∼95%. The increase in the reconstruction efficiency is caused by the increasing number of charged-particle tracks and a loose requirement on matching the track to the EM cluster. Finally, the electron identification is optimised to have a constant efficiency as a function of centrality and its value is
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Measurement of the $W$ boson polarisation in $t\bar{t}$ events from $pp$ collisions at $\sqrt{s}$ = 8 TeV in the lepton+jets channel with ATLAS

Measurement of the $W$ boson polarisation in $t\bar{t}$ events from $pp$ collisions at $\sqrt{s}$ = 8 TeV in the lepton+jets channel with ATLAS

2 The ATLAS detector The ATLAS experiment at the LHC is a multi-purpose particle detector with a forward-backward symmet- ric cylindrical geometry and a near 4π coverage in solid angle. 1 It consists of an inner tracking detector surrounded by a thin superconducting solenoid providing a 2 T axial magnetic field, electromagnetic and hadron calorimeters, and a muon spectrometer. The inner tracking detector covers the pseudorapidity range |η| < 2.5. It consists of silicon pixel, silicon microstrip, and transition-radiation tracking detect- ors. Lead/liquid-argon (LAr) sampling calorimeters provide electromagnetic energy measurements with high granularity. A hadron (steel/scintillator-tile) calorimeter covers the central pseudorapidity range (|η| < 1.7). The end-cap and forward regions are instrumented with LAr calorimeters for electromagnetic and hadronic energy measurements up to |η| = 4.9. The muon spectrometer surrounds the calorimeters and is based on three large air-core toroid superconducting magnets with eight coils each. Its bending power ranges from 2.0 to 7.5 T m. It includes a system of precision tracking chambers and fast detectors for triggering. A three-level trigger system is used to select events. The first-level trigger is implemented in hardware and uses a subset of the detector information to reduce the accepted rate to at most 75 kHz. This is followed by the high-level trigger, two software-based trigger levels that together reduce the ac- cepted event rate to 400 Hz on average depending on the data-taking conditions.
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Measurements of the W production cross sections in association with jets with the ATLAS detector

Measurements of the W production cross sections in association with jets with the ATLAS detector

cept the cut on E miss T ) to a sum of two templates: one for the multijet background and another which includes the signal and other background contributions. In both the muon and electron channels, the shape for the first template is obtained from data while the second tem- plate is from simulation. To select a data sample en- riched in multijet events in the electron channel, ded- icated electron triggers with loose identification crite- ria and additional triggers requiring electrons as well as jets are used. The multijet template is built from events which fail the “tight” requirements of the nominal elec- tron selection in order to suppress signal contamina- tion. Electrons are also required to be non-isolated in the calorimeter, i.e. they are required to have an energy deposition in the calorimeter in a cone of ∆R = 0.3 centred on the electron direction larger than 20% of the total transverse energy of the electron. In the muon channel, the multijet template is also obtained from
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Measurement of the W boson mass with the ATLAS detector

Measurement of the W boson mass with the ATLAS detector

Chapter 1 Theoretical background 1.1 Introduction The dream of all particle physicists is to understand how the Universe works from the most fundamental principles. The first attempts to describe nature with axioms is referred to ancient Greek philosophers. In particular, Democritus introduced the concept of atoms as small indivisible objects, called particles, that constitute matter. This has been allowed to describe all phenomena observed at that time as motion and collision of atoms in empty space. The huge amount of progress has been made since that time and now the Universe is proven to be much richer that makes it even more interesting to explore. As far as we understand it now, all of the matter around us is mostly composed of a few lightest elementary particles: the electron, the up quark and the down quark. There is also a slew of other elementary particles, but they are massive, and therefore forced to transform (or ‘decay‘) into less-weight particles. The need to consider such heavy particles as fundamental arises from the fact that they can be distinguished by unique characteristics, called quantum numbers. These particles interact through three fundamental forces - electromagnetic, strong and weak. The fourth known elementary force, the gravitational, is far too weak to cause a measurable effect at microscopic scale.
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Measurement of the ttbar production cross section in the tau+jets channel using the ATLAS detector

Measurement of the ttbar production cross section in the tau+jets channel using the ATLAS detector

6 Results An extended binned-likelihood fit is used to extract the different contributions from the n track distribution. To improve the fit stability, a soft constraint is applied to the ratio of quark-jet events to tau/electron events, which are dominated by the same process (t¯ t events). The constraint, based on MC predictions, is a Gaussian with a width of 19% of its central value. This width was estimated based on studies of the associated systematic uncertainties using the same methodology as described in Sect. 7. The statistical uncertainties on the fit param- eters are calculated using the shape of the fit likelihood. The systematic uncertainties on the shapes of the tem- plates are propagated using a pseudo-experiment ap- proach, taking into account the bin-by-bin correlations. This yields a final number of tau/electron events of 270 ± 24 (stat.) ± 11 (syst.).
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Measurement of the Higgs boson coupling properties in the $H\rightarrow ZZ^{*} \rightarrow 4\ell$ decay channel at $\sqrt{s}$ = 13 TeV with the ATLAS detector

Measurement of the Higgs boson coupling properties in the $H\rightarrow ZZ^{*} \rightarrow 4\ell$ decay channel at $\sqrt{s}$ = 13 TeV with the ATLAS detector

7 Background contributions The main source of background in the H → Z Z ∗ → 4` decay channel is non-resonant Z Z ∗ production with the same final state as the signal. This process, as well as a minor contribution from t ¯tV and triboson production, is modelled using simulation normalized to the highest-order SM prediction available. Additional reducible background sources are the Z +jets, t ¯t and WZ processes whose contributions in the signal region (SR) are estimated using dedicated signal-depleted control regions (CRs) in data, separately for events with different flavours of the subleading lepton pair (i.e. `` + µµ or `` + ee, where `` denotes the leading and µµ or ee the subleading lepton pair). No requirement is imposed on the four-lepton invariant mass in the control data. The backgrounds are first estimated for the inclusive event selection, i.e. prior to event categorization, and then divided into separate contributions in each reconstructed event category.
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Measurement of the $W^+W^-$ production cross section in $pp$ collisions at a centre-of-mass energy of $\sqrt{s}$ = 13 TeV with the ATLAS experiment

Measurement of the $W^+W^-$ production cross section in $pp$ collisions at a centre-of-mass energy of $\sqrt{s}$ = 13 TeV with the ATLAS experiment

1 Introduction The measurement of the production properties of opposite-charge W-boson pairs (denoted by WW in this Letter) is an important test of the Standard Model (SM) of particle physics. This process is sensitive to the strong interaction between quarks and gluons and probes the electroweak gauge structure of the SM. Measurements of WW production were first conducted at LEP [ 1 ] using electron–positron collisions. Measurements in hadron collisions were first carried out at the Tevatron by the CDF [ 2 , 3 ] and DØ [ 4 ] Collaborations. At the Large Hadron Collider (LHC), the WW production cross sections have been meas- ured in proton–proton collisions for centre-of-mass energies of √ s = 7 TeV and √ s = 8 TeV by the ATLAS [ 5 , 6 ] and CMS [ 7 , 8 ] Collaborations. In order to match the experimental precision and address discrepancies between data and theory reported in some of the 8 TeV results, significant progress has been made in theoretical calculations to include higher-order corrections in perturbative Quantum Chro- modynamics (pQCD) [ 9 – 14 ]. The WW signal is composed of three leading sub-processes: q ¯q → WW production 1 (in the t- and s-channels), non-resonant gg → WW production, and resonant gg → H → WW production (with both gg-initiated processes occurring through a quark loop). These sub-processes are known theoretically at di fferent orders in the strong coupling constant α s .
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Search for a heavy Standard Model Higgs boson in the channel H->ZZ->llqq using the ATLAS detector

Search for a heavy Standard Model Higgs boson in the channel H->ZZ->llqq using the ATLAS detector

The uncertainty in the normalization of the Z +jets background from the procedure described in Section 6 is evaluated by comparing the scale factors obtained from the upper or lower sideband separately. It is taken as the difference between the scale factors or the statistical uncertainty, whichever is larger. It is found to be 1.4% for the low-m H untagged selection, 8.1% for the high-m H untagged selection, and 18% for the tagged selections. The uncertainty on the shapes of the Z + jets (and ZZ) backgrounds is estimated using an alternate Monte Carlo sample generated with pythia instead of alpgen (or mc@nlo). The uncertainty on the t¯ t cross section is found by adding the contributions from variations of the QCD renormalization and factorization scales and from the cteq6.6 [34] parton distribution function (PDF) error set; the result is 9%. The diboson backgrounds, which are estimated directly from Monte Carlo, have a combined 5% scale and cteq6.6 PDF uncertainty on the cross section; adding an additional 10% uncertainty, corresponding to the maximum difference seen between mc@nlo and k-factor scaled pythia results, yields an overall uncertainty of 11%. A 100% systematic uncertainty is assigned to the normalization of the multijet background in the electron channel from the procedure described in Section 6 by comparing the result of fitting the m ℓℓ distribution before and after the requirement of at least two jets. The normalization uncertainty for the small W + jets background is taken to be 50%.
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Test of the universality of $\tau$ and $\mu$ lepton couplings in $W$-boson decays from $t\bar{t}$ events with the ATLAS detector

Test of the universality of $\tau$ and $\mu$ lepton couplings in $W$-boson decays from $t\bar{t}$ events with the ATLAS detector

G. Tarna 27b,d , G.F. Tartarelli 69a , P. Tas 142 , M. Tasevsky 140 , E. Tassi 41b,41a , A. Tavares Delgado 139a , Y. Tayalati 35e , A.J. Taylor 50 , G.N. Taylor 105 , W. Taylor 167b , H. Teagle 91 , A.S. Tee 90 , R. Teixeira De Lima 152 , P. Teixeira-Dias 94 , H. Ten Kate 36 , J.J. Teoh 120 , K. Terashi 162 , J. Terron 99 , S. Terzo 14 , M. Testa 51 , R.J. Teuscher 166,ab , S.J. Thais 182 , N. Themistokleous 50 , T. Theveneaux-Pelzer 46 , F. Thiele 40 , D.W. Thomas 94 , J.O. Thomas 42 , J.P. Thomas 21 , E.A. Thompson 46 , P.D. Thompson 21 , E. Thomson 136 , E.J. Thorpe 93 , R.E. Ticse Torres 53 , V.O. Tikhomirov 111,ah , Yu.A. Tikhonov 122b,122a , S. Timoshenko 112 , P. Tipton 182 , S. Tisserant 102 , K. Todome 23b,23a , S. Todorova-Nova 142 , S. Todt 48 , J. Tojo 88 , S. Tokár 28a , K. Tokushuku 82 , E. Tolley 127 , R. Tombs 32 , K.G. Tomiwa 33e , M. Tomoto 82,117 , L. Tompkins 152 , P. Tornambe 103 , E. Torrence 131 , H. Torres 48 , E. Torró Pastor 173 , M. Toscani 30 , C. Tosciri 134 , J. Toth 102,aa , D.R. Tovey 148 , A. Traeet 17 , C.J. Treado 125 , T. Trefzger 176 , F. Tresoldi 155 , A. Tricoli 29 , I.M. Trigger 167a , S. Trincaz-Duvoid 135 , D.A. Trischuk 174 , W. Trischuk 166 , B. Trocmé 58 , A. Trofymov 65 , C. Troncon 69a , F. Trovato 155 , L. Truong 33c , M. Trzebinski 85 , A. Trzupek 85 , F. Tsai 46 , J.C-L. Tseng 134 , P.V. Tsiareshka 108,ae , A. Tsirigotis 161,u , V. Tsiskaridze 154 , E.G. Tskhadadze 158a ,
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Measurement of the production cross-section of a single top quark in association with a $W$ boson at 8 TeV with the ATLAS experiment

Measurement of the production cross-section of a single top quark in association with a $W$ boson at 8 TeV with the ATLAS experiment

We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWFW and FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; CONICYT, Chile; CAS, MOST and NSFC, China; COLCIENCIAS, Colombia; MSMT CR, MPO CR and VSC CR, Czech Republic; DNRF, DNSRC and Lundbeck Foundation, Den- mark; IN2P3-CNRS, CEA-DSM/IRFU, France; GNSF, Georgia; BMBF, HGF, and MPG, Germany; GSRT, Greece; RGC, Hong Kong SAR, China; ISF, I-CORE and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; FOM and NWO, Netherlands; RCN, Norway; MNiSW and NCN, Poland; FCT, Portugal; MNE/IFA, Romania; MES of Russia and NRC KI, Russian Feder- ation; JINR; MESTD, Serbia; MSSR, Slovakia; ARRS and MIZŠ, Slovenia; DST /NRF, South Africa; MINECO, Spain; SRC and Wallenberg Foundation, Sweden; SERI, SNSF and Cantons of Bern and Geneva, Switzerland; MOST, Taiwan; TAEK, Turkey; STFC, United Kingdom; DOE and NSF, United States of America. In addition, individual groups and members have received support from BCKDF, the Canada Council, CANARIE, CRC, Compute Canada, FQRNT, and the Ontario Innovation Trust, Canada; EPLANET, ERC, FP7, Horizon 2020 and Marie Skłodowska-Curie Actions, European Union; Investisse- ments d’Avenir Labex and Idex, ANR, Region Auvergne and Fondation Partager le Savoir, France; DFG and AvH Foundation, Germany; Herakleitos, Thales and Aristeia programmes co-financed by EU-ESF and the Greek NSRF; BSF, GIF and Minerva, Israel; BRF, Norway; the Royal Society and Leverhulme Trust, United Kingdom.
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