Evidence of Wγγ Production in pp Collisions at s=8  TeV and Limits on Anomalous Quartic Gauge Couplings with the ATLAS Detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Phys.Rev.Lett. 115 (2015) 031802, 2015.
Inspire Record 1351760 DOI 10.17182/hepdata.45260

This Letter reports evidence of triple gauge boson production pp→W(ℓν)γγ+X, which is accessible for the first time with the 8 TeV LHC data set. The fiducial cross section for this process is measured in a data sample corresponding to an integrated luminosity of 20.3  fb-1, collected by the ATLAS detector in 2012. Events are selected using the W boson decay to eν or μν as well as requiring two isolated photons. The measured cross section is used to set limits on anomalous quartic gauge couplings in the high diphoton mass region.

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The measured inclusive ($N_{jet}\geq$ 0) fiducial cross section in the e$\nu\gamma\gamma$, $\mu\nu\gamma\gamma$ channels together with the combined $\ell\nu\gamma\gamma$ cross section. The first uncertainty shown is the statistical uncertainty on the measurement, the second one is the total systematic uncertainty (excluding the term coming from the luminosity), the third one is the systematic uncertainty coming from the luminosity. A parton to particle correction factors of 0.99 is applied to the MCFM prediction.

The measured exclusive ($N_{jet}$ = 0) fiducial cross section in the e$\nu\gamma\gamma$, $\mu\nu\gamma\gamma$ channels together with the combined $\ell\nu\gamma\gamma$ cross section. The first uncertainty shown is the statistical uncertainty on the measurement, the second one is the total systematic uncertainty (excluding the term coming from the luminosity), the third one is the systematic uncertainty coming from the luminosity. A parton to particle correction factor of 0.87 is applied to the MCFM prediction.

Observed and expected 95\% CL limits obtained for the $f_{\mathrm{T0}}/\Lambda^4$, $f_{\mathrm{M2}}/\Lambda^4$ and $f_{\mathrm{M3}}/\Lambda^4$ aQGC parameters for the combination of the two channels. The values of $n = 0,\,1,\,2$ are the exponential choices of the form factor, $\Lambda_{\rm{FF}}$ is fixed to $600$ GeV for $f_{\mathrm{T0}}/\Lambda^4$ and to $500$ GeV for the other parameters. The $n=0$ choice produces the limits without the form factor applied.


Fiducial particle-level differential cross-section, with statistical and systematic uncertainties, as a function of the top-jet candidate p_T.

Parton-level differential cross-section, with statistical and systematic uncertainties, as a function of the hadronically decaying top quark p_T.

The individual systematic uncertainties calculated as a percentage of the particle-level differential cross-section $d\sigma_{tt} / d p_{T,ptcl}$ in each bin. Variations on the two sides ("UP" and "DOWN") are separately quoted with their respective signs. Uncertainties smaller than 0.1% are neglected.

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Measurements of four-lepton production in $pp$ collisions at $\sqrt{s}=$ 8 TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Phys.Lett. B753 (2016) 552-572, 2016.
Inspire Record 1394865 DOI 10.17182/hepdata.18593

The four-lepton (4 ℓ , ℓ=e,μ ) production cross section is measured in the mass range from 80 to 1000 GeV using 20.3 fb −1 of data in pp collisions at s=8 TeV collected with the ATLAS detector at the LHC. The 4 ℓ events are produced in the decays of resonant Z and Higgs bosons and the non-resonant ZZ continuum originating from qq¯ , gg , and qg initial states. A total of 476 signal candidate events are observed with a background expectation of 26.2±3.6 events, enabling the measurement of the integrated cross section and the differential cross section as a function of the invariant mass and transverse momentum of the four-lepton system.

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The measured differential cross-section distributions in unit of fb/TeV of $m_{4\ell}$ unfolded into the fiducial phase space, and compared to theory predictions. The first uncertainty is statistical, the second is systematic uncertainties.

The measured differential cross-section distributions in unit of fb/TeV of $p_{T}^{4\ell}$ unfolded into the fiducial phase space, and compared to theory predictions. The first uncertainty is statistical, the second is systematic uncertainties.

Measured cross sections in the fiducial phase space ($\sigma^\mathrm{fid}$) and extended phase space ($\sigma^\mathrm{ext}$), compared to their SM predictions. One should note that the non-resonant $gg$-induced signal cross section is only calculated at LO approximation.

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Measurements of the Total and Differential Higgs Boson Production Cross Sections Combining the H→γγ and H→ZZ*→4ℓ Decay Channels at $\sqrt{s}$=8  TeV with the ATLAS Detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Phys.Rev.Lett. 115 (2015) 091801, 2015.
Inspire Record 1364361 DOI 10.17182/hepdata.57334

Measurements of the total and differential cross sections of Higgs boson production are performed using 20.3  fb-1 of pp collisions produced by the Large Hadron Collider at a center-of-mass energy of s=8  TeV and recorded by the ATLAS detector. Cross sections are obtained from measured H→γγ and H→ZZ*→4ℓ event yields, which are combined accounting for detector efficiencies, fiducial acceptances, and branching fractions. Differential cross sections are reported as a function of Higgs boson transverse momentum, Higgs boson rapidity, number of jets in the event, and transverse momentum of the leading jet. The total production cross section is determined to be σpp→H=33.0±5.3 (stat)±1.6 (syst)  pb. The measurements are compared to state-of-the-art predictions.

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Measured cross section in bins of $p_{\rm{T}}^{\rm{H}}$.

Measured cross section in bins of $|y^{\rm{H}}|$.

Measured cross section in bins of $N_{\rm{jets}}$.

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Search for charginos nearly mass degenerate with the lightest neutralino based on a disappearing-track signature in pp collisions at $\sqrt(s)$=8  TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abajyan, Tatevik ; Abbott, Brad ; et al.
Phys.Rev. D88 (2013) 112006, 2013.
Inspire Record 1258398 DOI 10.17182/hepdata.62699
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The pT distribution of disappearing-track candidates.

Observed CLs contour in the ( M(CHARGINO), TAU(CHARGINO) ) space for tan(beta) = 5 and mu > 0.

Observed CLs contour with minus 1-sigma signal cross-section uncertainty in the ( M(CHARGINO), TAU(CHARGINO) ) space for tan(beta) = 5 and mu > 0.

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Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in $\sqrt{s} =$ 8TeV $pp$ collisions with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abajyan, Tatevik ; Abbott, Brad ; et al.
JHEP 1404 (2014) 169, 2014.
Inspire Record 1282905 DOI 10.17182/hepdata.63114

A search for the direct production of charginos and neutralinos in final states with three leptons and missing transverse momentum is presented. The analysis is based on 20.3 fb-1 of sqrt(s) = 8 TeV proton--proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with the Standard Model expectations and limits are set in R-parity-conserving phenomenological Minimal Supersymmetric Standard Models and in simplified supersymmetric models, significantly extending previous results. For simplified supersymmetric models of direct chargino ($\tilde\chi^\pm_1$) and next-to-lightest neutralino ($\tilde{\chi}_2^0$) production with decays to lightest neutralino ($\tilde{\chi}_1^0$) via either all three generations of sleptons, staus only, gauge bosons, or Higgs bosons, $\tilde\chi^\pm_1$ and $\tilde{\chi}_2^0$ masses are excluded up to 700 GeV, 380 GeV, 345 GeV, or 148 GeV respectively, for a massless $\tilde{\chi}_1^0$.

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Number of expected and observed events in the validation region VR0taub.

For events in the low-ETmiss validation region, the MT distribution in VR0taunoZa.

For events in the low-ETmiss validation region, the MT distribution in VR0tauZa.

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Search for direct top squark pair production in events with a Z boson, b-jets and missing transverse momentum in sqrt(s)=8 TeV pp collisions with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Eur.Phys.J. C74 (2014) 2883, 2014.
Inspire Record 1286622 DOI 10.17182/hepdata.63210
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PT(ll) distribution in SR2A for stop GMSB model (data+/-stat, bkg+/-(stat+syst), signal+/-stat), m(stop1)=500 GeV, m(neutralino1)=400 GeV.

njet_3l (data+/-stat, bkg+/-(stat+syst), signal+/-stat).

Missing ET distribution in SR2A for stop GMSB model (data+/-stat, bkg+/-(stat+syst), signal+/-stat), m(stop1)=500 GeV, m(neutralino1)=400 GeV.

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Search for direct production of charginos, neutralinos and sleptons in final states with two leptons and missing transverse momentum in $pp$ collisions at $\sqrt{s} =$ 8 TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
JHEP 1405 (2014) 071, 2014.
Inspire Record 1286761 DOI 10.17182/hepdata.63216

Searches for the electroweak production of charginos, neutralinos and sleptons in final states characterized by the presence of two leptons (electrons and muons) and missing transverse momentum are performed using 20.3 fb-1 of proton-proton collision data at sqrt(s) = 8 TeV recorded with the ATLAS experiment at the Large Hadron Collider. No significant excess beyond Standard Model expectations is observed. Limits are set on the masses of the lightest chargino, next-to-lightest neutralino and sleptons for different lightest-neutralino mass hypotheses in simplified models. Results are also interpreted in various scenarios of the phenomenological Minimal Supersymmetric Standard Model.

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MT2 in WW CR for SR-WWa.

ET(miss,rel) in Top CR for SR-MT2 and SR-WWb/c.

ET(miss,rel) in ZV CR for SR-MT2 and SR-WWb/c.

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Search for heavy top-like quarks decaying to a Higgs boson and a top quark in the lepton plus jets final state in $pp$ collisions at $\sqrt{s}=8$ TeV with the ATLAS detector

The ATLAS collaboration
2013.
Inspire Record 1229964 DOI 10.17182/hepdata.61326

A search is presented for production of a heavy up-type quark ($t^\prime$) together with its antiparticle, assuming a significant branching ratio for subsequent $t^\prime$ decay into a Standard Model Higgs boson and a top quark, as predicted by vector-like quark models. The search is based on 14.3 fb$^{-1}$ of $pp$ collisions at $\sqrt{s}=8$ TeV recorded in 2012 with the ATLAS detector at the CERN Large Hadron Collider. Data are analysed in the lepton+jets final state, characterised by an isolated electron or muon with moderately high transverse momentum, significant missing transverse momentum, and at least six jets. The search exploits the high total transverse momenta of all final state objects and the high multiplicity of $b$ jets characteristic of signal events with at least one Higgs boson decaying into $b\bar{b}$, to discriminate against the dominant background from top quark pair production. No significant excess of events above the Standard Model expectation is observed, and upper limits are derived for vector-like quarks of various masses in the two-dimensional plane of $BR(t^\prime \to Wb)$ versus $BR(t^\prime \to Ht)$, where $H$ is the Standard Model Higgs boson, assumed to have a mass of $125$ GeV. Under the branching ratio assumptions corresponding to a weak-isospin doublet (singlet) scenario, a $t^\prime$ quark with mass lower than 790 (640) GeV is excluded at the 95\% confidence level.

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The observed and simulated HT distributions in the combined e+jets and mu+jets channels with >=6 jets and 2 b tagged jets.

The observed and simulated HT distributions in the combined e+jets and mu+jets channels with >=6 jets and 3 b tagged jets.

The observed and simulated HT distributions in the combined e+jets and mu+jets channels with >=6 jets and 4 b tagged jets.


Search for supersymmetry in events with four or more leptons in $\sqrt{s}$ = 8 TeV pp collisions with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Phys.Rev. D90 (2014) 052001, 2014.
Inspire Record 1297226 DOI 10.17182/hepdata.63284
93 data tables match query

The ETmiss distribution in VR0Z.

The effective mass distribution in VR0Z.

The ETmiss distribution in VR2Z.

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Search for supersymmetry at $\sqrt{s}$=8 TeV in final states with jets and two same-sign leptons or three leptons with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
JHEP 1406 (2014) 035, 2014.
Inspire Record 1289225 DOI 10.17182/hepdata.63682

A search for strongly produced supersymmetric particles is conducted using signatures involving multiple energetic jets and either two isolated leptons (e or μ) with the same electric charge, or at least three isolated leptons. The search also utilises jets originating from b-quarks, missing transverse momentum and other observables to extend its sensitivity. The analysis uses a data sample corresponding to a total integrated luminosity of 20.3 fb(−1) of = 8 TeV proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider in 2012. No deviation from the Standard Model expectation is observed. New or significantly improved exclusion limits are set on a wide variety of supersymmetric models in which the lightest squark can be of the first, second or third generations, and in which R-parity can be conserved or violated.

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Numbers of observed and background events for SR0b for each bin of the distribution in Meff. The table corresponds to Fig. 4(b). The statistical and systematic uncertainties are combined for the expected backgrounds.

Numbers of observed and background events for SR1b for each bin of the distribution in Meff. The table corresponds to Fig. 4(c). The statistical and systematic uncertainties are combined for the predicted numbers.

Numbers of observed and background events for SR3b for each bin of the distribution in Meff. The table corresponds to Fig. 4(a). The statistical and systematic uncertainties are combined for the predicted numbers.

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Measurement of the cross section of high transverse momentum $Z\rightarrow b\bar{b}$ production in proton--proton collisions at $\sqrt{s}=8 TeV$ with the ATLAS Detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Phys.Lett. B738 (2014) 25-43, 2014.
Inspire Record 1292799 DOI 10.17182/hepdata.64410
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The cross section for Z0 --> BOTTOM BOTTOMBAR measured in the fiducial region.


Search for $WZ$ resonances in the fully leptonic channel using $pp$ collisions at $\sqrt{s}$ = 8 TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Phys.Lett. B737 (2014) 223-243, 2014.
Inspire Record 1300821 DOI 10.17182/hepdata.65230

A search for resonant $WZ$ production in the $\ell\nu\ell'\ell'$ ($\ell, \ell' = e,\mu$) decay channel using 20.3 fb$^{-1}$ of $\sqrt{s}$ = 8 TeV $pp$ collision data collected by the ATLAS experiment at LHC is presented. No significant deviation from the Standard Model prediction is observed and upper limits on the production cross sections of $WZ$ resonances from an extended gauge model $W^{\prime}$ and from a simplified model of heavy vector triplets are derived. A corresponding observed (expected) lower mass limit of 1.52 (1.49) TeV is derived for the $W^{\prime}$ at the 95% confidence level.

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Search for new particles in events with one lepton and missing transverse momentum in $pp$ collisions at $\sqrt{s}$ = 8 TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
JHEP 1409 (2014) 037, 2014.
Inspire Record 1308524 DOI 10.17182/hepdata.65524

This paper presents a search for new particles in events with one lepton (electron or muon) and missing transverse momentum using 20.3 $fb^{-1}$ of proton-proton collision data at $\sqrt{s}=8$ TeV recorded by the ATLAS experiment at the Large Hadron Collider. No significant excess beyond Standard Model expectations is observed. A $W'$ with Sequential Standard Model couplings is excluded at the 95% confidence level for masses up to 3.24 TeV. Excited chiral bosons ($W^{*}$) with equivalent coupling strengths are excluded for masses up to 3.21 TeV. In the framework of an effective field theory limits are also set on the dark matter-nucleon scattering cross-section as well as the mass scale $M_{*}$ of the unknown mediating interaction for dark matter pair production in association with a leptonically decaying $W$.

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Spectrum of lepton PT for the electron channel after the event selection. The spectrum is shown with the requirement MT > 252 GeV.

Spectrum of lepton PT for the muon channel after the event selection. The spectrum is shown with the requirement MT > 252 GeV.

Spectrum of ETmiss for the electron channel after the event selection. The spectrum is shown with the requirement MT > 252 GeV.

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Search for supersymmetry in events with large missing transverse momentum, jets, and at least one tau lepton in 20 fb$^{-1}$ of $\sqrt{s}=$ 8 TeV proton-proton collision data with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
JHEP 1409 (2014) 103, 2014.
Inspire Record 1304458 DOI 10.17182/hepdata.65525

A search for supersymmetry (SUSY) in events with large missing transverse momentum, jets, at least one hadronically decaying tau lepton and zero or one additional light leptons (electron/muon), has been performed using 20.3fb$^{−1}$ of proton-proton collision data at $ \sqrt{s} $ = 8 TeV recorded with the ATLAS detector at the Large Hadron Collider. No excess above the Standard Model background expectation is observed in the various signal regions and 95% confidence level upper limits on the visible cross section for new phenomena are set. The results of the analysis are interpreted in several SUSY scenarios, significantly extending previous limits obtained in the same final states. In the framework of minimal gauge-mediated SUSY breaking models, values of the SUSY breaking scale Λ below 63 TeV are excluded, independently of tan β. Exclusion limits are also derived for an mSUGRA/CMSSM model, in both the R-parity-conserving and R-parity-violating case. A further interpretation is presented in a framework of natural gauge mediation, in which the gluino is assumed to be the only light coloured sparticle and gluino masses below 1090 GeV are excluded.

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Distribution of MTtau after all analysis requirements but the requirement on MTtau and the final requirement on HT for the 1tau ''Loose'' SR. The SM prediction includes the data-driven corrections discussed in the paper. MC events are normalized to data in the CRs corresponding to MTtau below 130 GeV. Also shown is the expected signal from typical mSUGRA, GMSB and bRPV samples. The last bin in the expected background distribution is an overflow bin.

Distribution of HT after the MTtau requirement for the 1-tau ''Loose'' SR. The SM prediction includes the data-driven corrections discussed in the paper. MC events are normalized to data in the CRs corresponding to MTtau below 130 GeV. Also shown is the expected signal from typical mSUGRA, GMSB and bRPV samples. The last bin in the expected background distribution is an overflow bin.

Distribution of MTtau after all analysis requirements but the requirement on MTtau and the final requirement on HT for the 1tau 'Tight'' SR. The SM prediction includes the data-driven corrections discussed in the paper. MC events are normalized to data in the CRs corresponding to MTtau below 130 GeV. Also shown is the expected signal from typical mSUGRA, GMSB and bRPV samples. The last bin in the expected background distribution is an overflow bin.