Evidence for Electroweak Production of $W^{\pm}W^{\pm}jj$ in $pp$ Collisions at $\sqrt{s}=8$ TeV with the ATLAS Detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Phys.Rev.Lett. 113 (2014) 141803, 2014.
Inspire Record 1298023 DOI 10.17182/hepdata.64182

This Letter presents the first study of $W^{\pm}W^{\pm}jj$, same-electric-charge diboson production in association with two jets, using 20.3 fb$^{-1}$ of proton--proton collision data at $\sqrt{s}=8$ TeV recorded by the ATLAS detector at the Large Hadron Collider. Events with two reconstructed same-charge leptons ($e^\pm e^\pm$, $e^\pm \mu^\pm$, and $\mu^\pm \mu^\pm$) and two or more jets are analyzed. Production cross sections are measured in two fiducial regions, with different sensitivities to the electroweak and strong production mechanisms. First evidence for $W^{\pm}W^{\pm}jj$ production and electroweak-only $W^{\pm}W^{\pm}jj$ production is observed with a significance of $4.5$ and $3.6$ standard deviations respectively. The measured production cross sections are in agreement with Standard Model predictions. Limits at 95% confidence level are set on anomalous quartic gauge couplings.

1 data table

The fiducial cross sections for the production of W+- W+- JET JET in the inclusive and VBS regions.


High-$E_{\rm T}$ isolated-photon plus jets production in $pp$ collisions at $\sqrt s=$ 8 TeV with the ATLAS detector

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Nucl.Phys.B 918 (2017) 257-316, 2017.
Inspire Record 1499475 DOI 10.17182/hepdata.79948

The dynamics of isolated-photon plus one-, two- and three-jet production in $pp$ collisions at a centre-of-mass energy of 8 TeV are studied with the ATLAS detector at the LHC using a data set with an integrated luminosity of 20.2 fb$^{-1}$. Measurements of isolated-photon plus jets cross sections are presented as functions of the photon and jet transverse momenta. The cross sections as functions of the azimuthal angle between the photon and the jets, the azimuthal angle between the jets, the photon-jet invariant mass and the scattering angle in the photon-jet centre-of-mass system are presented. The pattern of QCD radiation around the photon and the leading jet is investigated by measuring jet production in an annular region centred on each object; enhancements are observed around the leading jet with respect to the photon in the directions towards the beams. The experimental measurements are compared to several different theoretical calculations, and overall a good description of the data is found.

35 data tables

Measured cross sections for isolated-photon plus 1jet production as a function of $E_{\rm T}^{\gamma}$.

Measured cross sections for isolated-photon plus 1jet production as a function of $p_{\rm T}^{\rm jet1}$.

Measured cross sections for isolated-photon plus 1jet production as a function of $m^{\gamma-\rm jet1}$.

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Measurement of $W$ boson angular distributions in events with high transverse momentum jets at $\sqrt{s}=$ 8 TeV using the ATLAS detector

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Phys.Lett.B 765 (2017) 132-153, 2017.
Inspire Record 1487726 DOI 10.17182/hepdata.74701

The $W$ boson angular distribution in events with high transverse momentum jets is measured using data collected by the ATLAS experiment from proton-proton collisions at a centre-of-mass energy $\sqrt{s}=$ 8 TeV at the Large Hadron Collider, corresponding to an integrated luminosity of 20.3 fb$^{-1}$. The focus is on the contributions to $W$ + jets processes from real $W$ emission, which is achieved by studying events where a muon is observed close to a high transverse momentum jet. At small angular separations, these contributions are expected to be large. Various theoretical models of this process are compared to the data in terms of the absolute cross-section and the angular distributions of the muon from the leptonic $W$ decay.

5 data tables

Measured integrated cross-sections as a function of leading jet transverse momentum for the collinear region ($0.2 < \Delta R < 2.4$), the back-to-back region ($\Delta R > 2.4$) and inclusively.

Measured cross-section as a function of angular separation between the muon and the closest jet. Multiplicative correction factors for using prompt muons and prompt dressing photons in the particle-level selection, derived from ALPGEN 2.14 interfaced with PYTHIA 6.426, are also shown.

Breakdown of uncertainties in percent.

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Version 2
Measurement of differential cross sections and $W^+/W^-$ cross-section ratios for $W$ boson production in association with jets at $\sqrt{s}=8$ TeV with the ATLAS detector

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
JHEP 05 (2018) 077, 2018.
Inspire Record 1635273 DOI 10.17182/hepdata.80076

This paper presents a measurement of the $W$ boson production cross section and the $W^{+}/W^{-}$ cross-section ratio, both in association with jets, in proton--proton collisions at $\sqrt{s}=8$ TeV with the ATLAS experiment at the Large Hadron Collider. The measurement is performed in final states containing one electron and missing transverse momentum using data corresponding to an integrated luminosity of 20.2 fb$^{-1}$. Differential cross sections for events with one or two jets are presented for a range of observables, including jet transverse momenta and rapidities, the scalar sum of transverse momenta of the visible particles and the missing transverse momentum in the event, and the transverse momentum of the $W$ boson. For a subset of the observables, the differential cross sections of positively and negatively charged $W$ bosons are measured separately. In the cross-section ratio of $W^{+}/W^{-}$ the dominant systematic uncertainties cancel out, improving the measurement precision by up to a factor of nine. The observables and ratios selected for this paper provide valuable input for the up quark, down quark, and gluon parton distribution functions of the proton.

86 data tables

Cross section for the production of W bosons for different inclusive jet multiplicities.

Statistical correlation between bins in data for the cross section for the production of W bosons for different inclusive jet multiplicities.

Differential cross sections for the production of W<sup>+</sup> bosons, W<sup>-</sup> bosons and the W<sup>+</sup>/W<sup>-</sup> cross section ratio as a function of the inclusive jet multiplicity.

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Measurement of differential cross sections of isolated-photon plus heavy-flavour jet production in pp collisions at $\sqrt{s}=8$ TeV using the ATLAS detector

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
Phys.Lett.B 776 (2018) 295-317, 2018.
Inspire Record 1632756 DOI 10.17182/hepdata.79163

This Letter presents the measurement of differential cross sections of isolated prompt photons produced in association with a b-jet or a c-jet. These final states provide sensitivity to the heavy-flavour content of the proton and aspects related to the modelling of heavy-flavour quarks in perturbative QCD. The measurement uses proton-proton collision data at a centre-of-mass energy of 8 TeV recorded by the ATLAS detector at the LHC in 2012 corresponding to an integrated luminosity of up to 20.2 fb$^{-1}$. The differential cross sections are measured for each jet flavour with respect to the transverse energy of the leading photon in two photon pseudorapidity regions: $|\eta^\gamma|<1.37$ and $1.56<|\eta^\gamma|<2.37$. The measurement covers photon transverse energies $25 < E_\textrm{T}^\gamma<400$ GeV and $25 < E_\textrm{T}^\gamma<350$ GeV respectively for the two $|\eta^\gamma|$ regions. For each jet flavour, the ratio of the cross sections in the two $|\eta^\gamma|$ regions is also measured. The measurement is corrected for detector effects and compared to leading-order and next-to-leading-order perturbative QCD calculations, based on various treatments and assumptions about the heavy-flavour content of the proton. Overall, the predictions agree well with the measurement, but some deviations are observed at high photon transverse energies. The total uncertainty in the measurement ranges between 13% and 66%, while the central $\gamma+b$ measurement exhibits the smallest uncertainty, ranging from 13% to 27%, which is comparable to the precision of the theoretical predictions.

12 data tables

Measured fiducial integrated $\gamma+b$ and $\gamma+c$ cross sections for $|\eta^\gamma|<1.37$ and $1.56<|\eta^\gamma|<2.37$.

Measured $\gamma+b$ fiducial differential cross section as a function of $E_\text{T}^\gamma$ for $|\eta^\gamma|<1.37$.

Measured $\gamma+b$ fiducial differential cross section as a function of $E_\text{T}^\gamma$ for $1.56<|\eta^\gamma|<2.37$.

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Measurement of the electroweak production of dijets in association with a Z-boson and distributions sensitive to vector boson fusion in proton-proton collisions at sqrt(s) = 8 TeV using the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abajyan, Tatevik ; Abbott, Brad ; et al.
JHEP 04 (2014) 031, 2014.
Inspire Record 1279489 DOI 10.17182/hepdata.62729

Measurements of fiducial cross sections for the electroweak production of two jets in association with a Z-boson are presented. The measurements are performed using 20.3 inverse femtobarns of proton-proton collision data collected at a centre-of-mass energy of sqrt(s)=8 TeV by the ATLAS experiment at the Large Hadron Collider. The electroweak component is extracted by a fit to the dijet invariant mass distribution in a fiducial region chosen to enhance the electroweak contribution over the dominant background in which the jets are produced via the strong interaction. The electroweak cross sections measured in two fiducial regions are in good agreement with the Standard Model expectations and the background-only hypothesis is rejected with significance above the 5 sigma level. The electroweak process includes the vector boson fusion production of a Z-boson and the data are used to place limits on anomalous triple gauge boson couplings. In addition, measurements of cross sections and differential distributions for inclusive Z-boson-plus-dijet production are performed in five fiducial regions, each with different sensitivity to the electroweak contribution. The results are corrected for detector effects and compared to predictions from the SHERPA and POWHEG event generators.

23 data tables

Unfolded normalised differential Z+2j cross section as a function of dijet invariant mass in the baseline region.

Unfolded normalised differential Z+2j cross section as a function of dijet invariant mass in the search region.

Unfolded normalised differential Z+2j cross section as a function of the rapidity separation between the leading jets in the baseline region.

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Measurement of the production cross section of the W boson in association with two b jets in pp collisions at sqrt(s) = 8 TeV

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M ; Tumasyan, Armen ; et al.
Eur.Phys.J.C 77 (2017) 92, 2017.
Inspire Record 1484162 DOI 10.17182/hepdata.76543

The production cross section of a W boson in association with two b jets is measured using a sample of proton-proton collisions at sqrt(s) = 8 TeV collected by the CMS experiment at the CERN LHC. The data sample corresponds to an integrated luminosity of 19.8 inverse femtobarns. The W bosons are reconstructed via their leptonic decays, W to l nu, where l = mu or e. The fiducial region studied contains exactly one lepton with transverse momentum pt[l] > 30 GeV and pseudorapidity abs(eta[l]) < 2.1, with exactly two b jets with pt > 25 GeV and abs(eta) < 2.4 and no other jets with pt > 25 GeV and abs(eta) < 4.7. The cross section is measured to be sigma(pp to W (l nu)+ bb-bar) = 0.64 +/- 0.03 (stat) +/- 0.10 (syst) +/- 0.06 (theo) +/- 0.02 (lumi) pb, in agreement with standard model predictions.

1 data table

Wbb production cross section in pb.


Measurements of fiducial cross-sections for $t\bar{t}$ production with one or two additional $b$-jets in $pp$ collisions at $\sqrt{s}$ = 8 TeV using the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Eur.Phys.J.C 76 (2016) 11, 2016.
Inspire Record 1390114 DOI 10.17182/hepdata.72856

Fiducial cross-sections for $t\bar{t}$ production with one or two additional $b$-jets are reported, using an integrated luminosity of 20.3 fb$^{-1}$ of proton--proton collisions at a centre-of-mass energy of 8 TeV at the Large Hadron Collider, collected with the ATLAS detector. The cross-section times branching ratio for $t\bar{t}$ events with at least one additional $b$-jet is measured to be 950 $\pm$ 70 (stat.) $^{+240}_{-190}$ (syst.) fb in the lepton-plus-jets channel and 50 $\pm$ 10 (stat.) $^{+15}_{-10}$ (syst.) fb in the $e \mu$ channel. The cross-section times branching ratio for events with at least two additional $b$-jets is measured to be 19.3 $\pm$ 3.5 (stat.) $\pm$ 5.7 (syst.) fb in the dilepton channel ($e \mu$,\,$\mu\mu$, and \,$ee$) using a method based on tight selection criteria, and 13.5 $\pm$ 3.3 (stat.) $\pm$ 3.6 (syst.) fb using a looser selection that allows the background normalisation to be extracted from data. The latter method also measures a value of 1.30 $\pm$ 0.33 (stat.) $\pm$ 0.28 (syst.)\% for the ratio of $t\bar{t}$ production with two additional $b$-jets to $t\bar{t}$ production with any two additional jets. All measurements are in good agreement with recent theory predictions.

8 data tables

Measured fiducial cross section for $t\bar{t}$ events with exactly one lepton and at least five jets, of which at least three are b-jets. The definition of the cross-section includes $t\bar{t}+Z / H$ events that pass the fiducial requirements.

Measured fiducial cross section for $t\bar{t}$ events with two leptons and at least three b-jets. The definition of the cross-section includes $t\bar{t}+Z / H$ events that pass the fiducial requirements.

Measured fiducial cross section for $t\bar{t}$ events with two leptons and at least four b-jets. The definition of the cross-section includes $t\bar{t}+Z / H$ events that pass the fiducial requirements.

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Measurements of the differential production cross sections for a Z boson in association with jets in pp collisions at sqrt(s) = 8 TeV

The CMS collaboration Khachatryan, Vardan ; Sirunyan, Albert M ; Tumasyan, Armen ; et al.
JHEP 04 (2017) 022, 2017.
Inspire Record 1497519 DOI 10.17182/hepdata.128149

Cross sections for the production of a Z boson in association with jets in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 8 TeV are measured using a data sample collected by the CMS experiment at the LHC corresponding to 19.6 inverse femtobarns. Differential cross sections are presented as functions of up to three observables that describe the jet kinematics and the jet activity. Correlations between the azimuthal directions and the rapidities of the jets and the Z boson are studied in detail. The predictions of a number of multileg generators with leading or next-to-leading order accuracy are compared with the measurements. The comparison shows the importance of including multi-parton contributions in the matrix elements and the improvement in the predictions when next-to-leading order terms are included.

128 data tables

The cross section for Z($\rightarrow\ell\ell$) + jets production measured as a function of the exclusive jet multiplicity, $N_{\text{jets}}$, and breakdown of the relative uncertainty.

Bin-to-bin correlation in the the cross section for Z($\rightarrow\ell\ell$) + jets production measured as a function of the exclusive jet multiplicity, $N_{\text{jets}}$.

The cross section for Z($\rightarrow\ell\ell$) + jets production measured as a function of the 1$^\text{st}$ jet $p_{\text{T}}$, $p_{\text{T}}(\text{j}_1)$, and breakdown of the relative uncertainty.

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Search for New Phenomena in Dijet Angular Distributions in Proton-Proton Collisions at $\sqrt{s} = 8$ TeV Measured with the ATLAS Detector

The ATLAS collaboration Aad, Georges ; Abbott, Brad ; Abdallah, Jalal ; et al.
Phys.Rev.Lett. 114 (2015) 221802, 2015.
Inspire Record 1357594 DOI 10.17182/hepdata.68404

A search for new phenomena in LHC proton-proton collisions at a center-of-mass energy of $\sqrt{s}=8$ TeV was performed with the ATLAS detector using an integrated luminosity of 17.3 fb$^{-1}$. The angular distributions are studied in events with at least two jets; the highest dijet mass observed is 5.5 TeV. All angular distributions are consistent with the predictions of the Standard Model. In a benchmark model of quark contact interactions, a compositeness scale below 8.1 TeV in a destructive interference scenario and 12.0 TeV in a constructive interference scenario is excluded at 95 % CL; median expected limits are 8.9 TeV for the destructive interference scenario and 14.1 TeV for the constructive interference scenario.

7 data tables

mjj region 600 - 800 GeV. The observed systematic is the experimental uncertainty, while the SM prediction systematic is the theoretical uncertainty.

mjj region 800 - 1200 GeV. The observed systematic is the experimental uncertainty, while the SM prediction systematic is the theoretical uncertainty.

mjj region 1200 - 1600 GeV. The observed systematic is the experimental uncertainty, while the SM prediction systematic is the theoretical uncertainty.

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