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24,454 Research products, page 1 of 2,446

  • Canada
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  • 2012-2021
  • Natural Sciences and Engineering Research Council of Canada

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  • English
    Authors: 
    ATLAS Collaboration;
    Publisher: HEPData
    Project: NSERC

    - CERN-LHC. This article presents measurements of the $t$-channel single top-quark $(t)$ and top-antiquark $(\bar t)$ total production cross sections $\sigma(tq)$ and $\sigma(\bar tq)$, their ratio $R_{t}=\sigma(tq)/\sigma(\bar tq)$, and a measurement of the inclusive production cross section $\sigma(tq+\bar tq)$ in proton-proton collisions at $\sqrt{s}~=~7~\mathrm{TeV}$ at the LHC. Differential cross sections for the $tq$ and $\bar tq$ processes are measured as a function of the transverse momentum and the absolute value of the rapidity of $t$ and $\bar t$, respectively. The analyzed data set was recorded with the ATLAS detector and corresponds to an integrated luminosity of $4.59~\mathrm{fb}^{-1}$. Selected events contain one charged lepton, large missing transverse momentum, and two or three jets. The cross sections are measured by performing a binned maximum-likelihood fit to the output distributions of neural networks. The resulting measurements are $\sigma(tq)=46 \pm 1(\mathrm{stat})\pm 6(\mathrm{syst})~\mathrm{pb}$, $\sigma(\bar tq)=23 \pm 1(\mathrm{stat})\pm 3(\mathrm{syst})~\mathrm{pb}$, $R_{t}=2.04 \pm 0.13(\mathrm{stat})\pm 0.12(\mathrm{syst})$, and $\sigma(tq+\bar tq)=68 \pm 2(\mathrm{stat})\pm 8(\mathrm{syst})~\mathrm{pb}$, consistent with the Standard Model expectation. The uncertainty on the measured cross sections is dominated by systematic uncertainties, while the uncertainty on $R_{t}$ is mainly statistical. Using the ratio of $\sigma(tq+\bar tq)$ to its theoretical prediction, and assuming that the top-quark-related CKM matrix elements obey the relation $|V_{tb}|\gg |V_{ts}|$, $|V_{td}|$, we determine $|V_{tb}|=1.02 \pm 0.07$. Detailed list of the contribution of each source of uncertainty to the total relative uncertainty on the measured $\dfrac{\mathrm{d}\sigma}{\mathrm{d}|y(t)|}$ distribution given in percent for each bin. The list includes only those uncertainties that contribute with more than $1\%$. The following uncertainties contribute to the total uncertainty with less than $1\%$ to each bin content$:$ JES detector, JES statistical, JES physics modeling, JES mixed detector and modeling, JES close-by jets, JES pileup, JES flavor composition, JES flavor response, jet-vertex fraction, $b/\bar{b}$ acceptance, $E_{\mathrm{T}}^{\mathrm{miss}}$ modeling, $W+$ jets shape variation, $t \bar{t}$ generator, $t \bar{t}$ ISR/FSR, and unfolding. In cases when the uncertainty is report to be "$<1\%$" in the table of the paper the uncertainty is approximated by a value of $0.5\%$.

  • English
    Authors: 
    ATLAS Collaboration;
    Publisher: HEPData
    Project: NSERC

    CERN-LHC. Studies of the fragmentation of jets into charged particles in heavy-ion collisions can provide information about the mechanism of jet-quenching by the hot and dense QCD matter created in such collisions, the quark-gluon plasma. This paper presents a measurement of the angular distribution of charged particles around the jet axis in sNN=5.02 TeV Pb+Pb and pp collisions, using the ATLAS detector at the LHC. The Pb+Pb and pp data sets have integrated luminosities of 0.49 nb−1 and 25 pb−1, respectively. The measurement is performed for jets reconstructed with the anti-kt algorithm with radius parameter R=0.4 and is extended to an angular distance of r=0.8 from the jet axis. Results are presented as a function of Pb+Pb collision centrality and distance from the jet axis for charged particles with transverse momenta in the 1−63 GeV range, matched to jets with transverse momenta in the 126−316 GeV range and an absolute value of jet rapidity of less than 1.7. Modifications to the measured distributions are quantified by taking a ratio to the measurements in pp collisions. Yields of charged particles with transverse momenta below 4 GeV are observed to be increasingly enhanced as a function of angular distance from the jet axis, reaching a maximum at r=0.6. Charged particles with transverse momenta above 4 GeV have an enhanced yield in Pb+Pb collisions in the jet core for angular distances up to r=0.05 from the jet axis, with a suppression at larger distances. From Fig 9. Delta_D(pT,r) The differences between charged particle distributions around jets as a function of distance from the jet axis in different centrality intervals of PbPb and pp collisions at 5.02 TeV for different track pT and jet pT ranges.

  • Open Access
    Authors: 
    Mroue, Abdul; Boyle, Michael; Lovelace, Geoffrey; Szilagyi, Bela; Pfeiffer, Harald; Zenginoglu, Anil; Kidder, Larry; Taylor, Nicholas; Hemberger, Dan; Scheel, Mark;
    Publisher: Zenodo
    Project: NSERC , NSF | Gravitational Radiation a... (1068881), NSF | Collaborative Research: D... (1005655), NSF | Research in Black-Hole Ph... (0969111), NSF | MRI-R2: Acquisition of a ... (0960291), NSF | Collaborative Research: D... (1005426), NSF | FRG: Collaborative Resear... (1065438)

    Simulation of a black-hole binary system evolved by the SpEC code.

  • English
    Authors: 
    Cao, Levy L.; Zhou, Jiliang; Qu, Zheng-Wang; Stephan, Douglas W.;
    Publisher: Cambridge Crystallographic Data Centre
    Project: NSERC

    Related Article: Levy L. Cao, Jiliang Zhou, Zheng-Wang Qu, Douglas W. Stephan|2019|Angew.Chem.,Int.Ed.|58|18487|doi:10.1002/anie.201912338

  • English
    Authors: 
    ATLAS Collaboration;
    Publisher: HEPData
    Project: NSERC

    No data abstract available. SRC for p+Pb, pT>0.5GeV

  • Open Access
    Authors: 
    Kidder, Larry; Lovelace, Geoffrey; Hemberger, Dan; Pfeiffer, Harald; Boyle, Michael; Scheel, Mark; Mroue, Abdul; Taylor, Nicholas; Szilagyi, Bela; Zenginoglu, Anil;
    Publisher: Zenodo
    Project: NSF | MRI-R2: Acquisition of a ... (0960291), NSERC , NSF | Maximizing Scientific Out... (1806665), NSF | Collaborative Research: P... (1713694), NSF | Gravitational Radiation a... (1708213), NSF | FRG: Collaborative Resear... (1065438), NSF | Leadership Class Scientif... (0725070), NSF | Collaborative Research: D... (1005655), NSF | Sustained-Petascale In Ac... (1238993), NWO | Precision Gravity: black ... (29769),...

    Simulation of a black-hole binary system evolved by the SpEC code.

  • English
    Authors: 
    ATLAS Collaboration;
    Publisher: HEPData
    Project: NSERC

    CERN-LHC. A search for the supersymmetric partners of quarks and gluons (squarks and gluinos) in final states containing hadronic jets and missing transverse momentum, but no electrons or muons, is presented. The data used in this search were recorded in 2015 and 2016 by the ATLAS experiment in $\sqrt{s}=13\mathrm{\ Te\kern -0.1em V}$ proton--proton collisions at the Large Hadron Collider, corresponding to an integrated luminosity of 36.1 fb$^{-1}$. The results are interpreted in the context of various models where squarks and gluinos are pair-produced and the neutralino is the lightest supersymmetric particle. An exclusion limit at the 95% confidence level on the mass of the gluino is set at 2.03$\mathrm{\ Te\kern -0.1em V}$ for a simplified model incorporating only a gluino and the lightest neutralino, assuming the lightest neutralino is massless. For a simplified model involving the strong production of mass-degenerate first- and second-generation squarks, squark masses below 1.55$\mathrm{\ Te\kern -0.1em V}$ are excluded if the lightest neutralino is massless. These limits substantially extend the region of supersymmetric parameter space previously excluded by searches with the ATLAS detector. Signal region efficiency for simplified model with squark pair production and decays to a quark and chargino in SR RJR-C4.

  • English
    Authors: 
    Robidas, Raphaël; Guérin, Vincent; Provençal, Laurent; Echeverria, Marco; Legault, Claude Y.;
    Publisher: Cambridge Crystallographic Data Centre
    Project: NSERC

    An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures. Related Article: Raphaël Robidas, Vincent Guérin, Laurent Provençal, Marco Echeverria, Claude Y. Legault|2017|Org.Lett.|19|6420|doi:10.1021/acs.orglett.7b03307

  • English
    Authors: 
    ATLAS Collaboration;
    Publisher: HEPData
    Project: NSERC

    A search for new phenomena in final states with hadronically decaying tau leptons, b-jets, and missing transverse momentum is presented. The analyzed dataset comprises pp collision data at a center-of-mass energy of 13 TeV with an integrated luminosity of 139/fb, delivered by the Large Hadron Collider and recorded with the ATLAS detector from 2015 to 2018. The observed data are compatible with the expected Standard Model background. The results are interpreted in simplified models for two different scenarios. The first model considers pair production of supersymmetric top squarks, each of which decays into a b-quark, a neutrino and a supersymmetric tau slepton. Each tau slepton in turn decays into a tau lepton and a nearly massless supersymmetric gravitino. Within this model, top-squark masses of 1.4 TeV can be excluded at the 95% confidence level over a wide range of tau-slepton masses. The second model considers pair production of leptoquarks with decays into third-generation leptons and quarks. Depending on the branching fraction into charged leptons, leptoquarks with masses up to around 1.25 TeV can be excluded at the 95% confidence level for the case of scalar leptoquarks and up to 1.8 TeV (1.5 TeV) for vector leptoquarks in a Yang–Mills (minimal-coupling) scenario. In addition, model-independent upper limits are set on the cross section of processes beyond the Standard Model. Expected and observed exclusion contours at the 95% confidence level for the vector third-generation leptoquark signal model, as a function of the mass $m(\text{LQ}_{3}^{\text{v}})$ and the branching fraction $B(\text{LQ}_{3}^{\text{v}} \rightarrow b\tau)$ into a quark and a charged lepton. The plot shows the exclusion contour for vector leptoquarks with additional gauge couplings. The limits are derived from the binned single-tau signal region.

  • Open Access
    Authors: 
    Mroue, Abdul; Boyle, Michael; Lovelace, Geoffrey; Szilagyi, Bela; Pfeiffer, Harald; Zenginoglu, Anil; Kidder, Larry; Taylor, Nicholas; Hemberger, Dan; Scheel, Mark;
    Publisher: Zenodo
    Project: NSERC , NSF | Collaborative Research: D... (1005426), NSF | FRG: Collaborative Resear... (1065438), NSF | Collaborative Research: D... (1005655), NSF | MRI-R2: Acquisition of a ... (0960291), NSF | Research in Black-Hole Ph... (0969111), NSF | Gravitational Radiation a... (1068881)

    Simulation of a black-hole binary system evolved by the SpEC code.

search
Include:
The following results are related to Canada. Are you interested to view more results? Visit OpenAIRE - Explore.
24,454 Research products, page 1 of 2,446
  • English
    Authors: 
    ATLAS Collaboration;
    Publisher: HEPData
    Project: NSERC

    - CERN-LHC. This article presents measurements of the $t$-channel single top-quark $(t)$ and top-antiquark $(\bar t)$ total production cross sections $\sigma(tq)$ and $\sigma(\bar tq)$, their ratio $R_{t}=\sigma(tq)/\sigma(\bar tq)$, and a measurement of the inclusive production cross section $\sigma(tq+\bar tq)$ in proton-proton collisions at $\sqrt{s}~=~7~\mathrm{TeV}$ at the LHC. Differential cross sections for the $tq$ and $\bar tq$ processes are measured as a function of the transverse momentum and the absolute value of the rapidity of $t$ and $\bar t$, respectively. The analyzed data set was recorded with the ATLAS detector and corresponds to an integrated luminosity of $4.59~\mathrm{fb}^{-1}$. Selected events contain one charged lepton, large missing transverse momentum, and two or three jets. The cross sections are measured by performing a binned maximum-likelihood fit to the output distributions of neural networks. The resulting measurements are $\sigma(tq)=46 \pm 1(\mathrm{stat})\pm 6(\mathrm{syst})~\mathrm{pb}$, $\sigma(\bar tq)=23 \pm 1(\mathrm{stat})\pm 3(\mathrm{syst})~\mathrm{pb}$, $R_{t}=2.04 \pm 0.13(\mathrm{stat})\pm 0.12(\mathrm{syst})$, and $\sigma(tq+\bar tq)=68 \pm 2(\mathrm{stat})\pm 8(\mathrm{syst})~\mathrm{pb}$, consistent with the Standard Model expectation. The uncertainty on the measured cross sections is dominated by systematic uncertainties, while the uncertainty on $R_{t}$ is mainly statistical. Using the ratio of $\sigma(tq+\bar tq)$ to its theoretical prediction, and assuming that the top-quark-related CKM matrix elements obey the relation $|V_{tb}|\gg |V_{ts}|$, $|V_{td}|$, we determine $|V_{tb}|=1.02 \pm 0.07$. Detailed list of the contribution of each source of uncertainty to the total relative uncertainty on the measured $\dfrac{\mathrm{d}\sigma}{\mathrm{d}|y(t)|}$ distribution given in percent for each bin. The list includes only those uncertainties that contribute with more than $1\%$. The following uncertainties contribute to the total uncertainty with less than $1\%$ to each bin content$:$ JES detector, JES statistical, JES physics modeling, JES mixed detector and modeling, JES close-by jets, JES pileup, JES flavor composition, JES flavor response, jet-vertex fraction, $b/\bar{b}$ acceptance, $E_{\mathrm{T}}^{\mathrm{miss}}$ modeling, $W+$ jets shape variation, $t \bar{t}$ generator, $t \bar{t}$ ISR/FSR, and unfolding. In cases when the uncertainty is report to be "$<1\%$" in the table of the paper the uncertainty is approximated by a value of $0.5\%$.

  • English
    Authors: 
    ATLAS Collaboration;
    Publisher: HEPData
    Project: NSERC

    CERN-LHC. Studies of the fragmentation of jets into charged particles in heavy-ion collisions can provide information about the mechanism of jet-quenching by the hot and dense QCD matter created in such collisions, the quark-gluon plasma. This paper presents a measurement of the angular distribution of charged particles around the jet axis in sNN=5.02 TeV Pb+Pb and pp collisions, using the ATLAS detector at the LHC. The Pb+Pb and pp data sets have integrated luminosities of 0.49 nb−1 and 25 pb−1, respectively. The measurement is performed for jets reconstructed with the anti-kt algorithm with radius parameter R=0.4 and is extended to an angular distance of r=0.8 from the jet axis. Results are presented as a function of Pb+Pb collision centrality and distance from the jet axis for charged particles with transverse momenta in the 1−63 GeV range, matched to jets with transverse momenta in the 126−316 GeV range and an absolute value of jet rapidity of less than 1.7. Modifications to the measured distributions are quantified by taking a ratio to the measurements in pp collisions. Yields of charged particles with transverse momenta below 4 GeV are observed to be increasingly enhanced as a function of angular distance from the jet axis, reaching a maximum at r=0.6. Charged particles with transverse momenta above 4 GeV have an enhanced yield in Pb+Pb collisions in the jet core for angular distances up to r=0.05 from the jet axis, with a suppression at larger distances. From Fig 9. Delta_D(pT,r) The differences between charged particle distributions around jets as a function of distance from the jet axis in different centrality intervals of PbPb and pp collisions at 5.02 TeV for different track pT and jet pT ranges.

  • Open Access
    Authors: 
    Mroue, Abdul; Boyle, Michael; Lovelace, Geoffrey; Szilagyi, Bela; Pfeiffer, Harald; Zenginoglu, Anil; Kidder, Larry; Taylor, Nicholas; Hemberger, Dan; Scheel, Mark;
    Publisher: Zenodo
    Project: NSERC , NSF | Gravitational Radiation a... (1068881), NSF | Collaborative Research: D... (1005655), NSF | Research in Black-Hole Ph... (0969111), NSF | MRI-R2: Acquisition of a ... (0960291), NSF | Collaborative Research: D... (1005426), NSF | FRG: Collaborative Resear... (1065438)

    Simulation of a black-hole binary system evolved by the SpEC code.

  • English
    Authors: 
    Cao, Levy L.; Zhou, Jiliang; Qu, Zheng-Wang; Stephan, Douglas W.;
    Publisher: Cambridge Crystallographic Data Centre
    Project: NSERC

    Related Article: Levy L. Cao, Jiliang Zhou, Zheng-Wang Qu, Douglas W. Stephan|2019|Angew.Chem.,Int.Ed.|58|18487|doi:10.1002/anie.201912338

  • English
    Authors: 
    ATLAS Collaboration;
    Publisher: HEPData
    Project: NSERC

    No data abstract available. SRC for p+Pb, pT>0.5GeV

  • Open Access
    Authors: 
    Kidder, Larry; Lovelace, Geoffrey; Hemberger, Dan; Pfeiffer, Harald; Boyle, Michael; Scheel, Mark; Mroue, Abdul; Taylor, Nicholas; Szilagyi, Bela; Zenginoglu, Anil;
    Publisher: Zenodo
    Project: NSF | MRI-R2: Acquisition of a ... (0960291), NSERC , NSF | Maximizing Scientific Out... (1806665), NSF | Collaborative Research: P... (1713694), NSF | Gravitational Radiation a... (1708213), NSF | FRG: Collaborative Resear... (1065438), NSF | Leadership Class Scientif... (0725070), NSF | Collaborative Research: D... (1005655), NSF | Sustained-Petascale In Ac... (1238993), NWO | Precision Gravity: black ... (29769),...

    Simulation of a black-hole binary system evolved by the SpEC code.

  • English
    Authors: 
    ATLAS Collaboration;
    Publisher: HEPData
    Project: NSERC

    CERN-LHC. A search for the supersymmetric partners of quarks and gluons (squarks and gluinos) in final states containing hadronic jets and missing transverse momentum, but no electrons or muons, is presented. The data used in this search were recorded in 2015 and 2016 by the ATLAS experiment in $\sqrt{s}=13\mathrm{\ Te\kern -0.1em V}$ proton--proton collisions at the Large Hadron Collider, corresponding to an integrated luminosity of 36.1 fb$^{-1}$. The results are interpreted in the context of various models where squarks and gluinos are pair-produced and the neutralino is the lightest supersymmetric particle. An exclusion limit at the 95% confidence level on the mass of the gluino is set at 2.03$\mathrm{\ Te\kern -0.1em V}$ for a simplified model incorporating only a gluino and the lightest neutralino, assuming the lightest neutralino is massless. For a simplified model involving the strong production of mass-degenerate first- and second-generation squarks, squark masses below 1.55$\mathrm{\ Te\kern -0.1em V}$ are excluded if the lightest neutralino is massless. These limits substantially extend the region of supersymmetric parameter space previously excluded by searches with the ATLAS detector. Signal region efficiency for simplified model with squark pair production and decays to a quark and chargino in SR RJR-C4.

  • English
    Authors: 
    Robidas, Raphaël; Guérin, Vincent; Provençal, Laurent; Echeverria, Marco; Legault, Claude Y.;
    Publisher: Cambridge Crystallographic Data Centre
    Project: NSERC

    An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures. Related Article: Raphaël Robidas, Vincent Guérin, Laurent Provençal, Marco Echeverria, Claude Y. Legault|2017|Org.Lett.|19|6420|doi:10.1021/acs.orglett.7b03307

  • English
    Authors: 
    ATLAS Collaboration;
    Publisher: HEPData
    Project: NSERC

    A search for new phenomena in final states with hadronically decaying tau leptons, b-jets, and missing transverse momentum is presented. The analyzed dataset comprises pp collision data at a center-of-mass energy of 13 TeV with an integrated luminosity of 139/fb, delivered by the Large Hadron Collider and recorded with the ATLAS detector from 2015 to 2018. The observed data are compatible with the expected Standard Model background. The results are interpreted in simplified models for two different scenarios. The first model considers pair production of supersymmetric top squarks, each of which decays into a b-quark, a neutrino and a supersymmetric tau slepton. Each tau slepton in turn decays into a tau lepton and a nearly massless supersymmetric gravitino. Within this model, top-squark masses of 1.4 TeV can be excluded at the 95% confidence level over a wide range of tau-slepton masses. The second model considers pair production of leptoquarks with decays into third-generation leptons and quarks. Depending on the branching fraction into charged leptons, leptoquarks with masses up to around 1.25 TeV can be excluded at the 95% confidence level for the case of scalar leptoquarks and up to 1.8 TeV (1.5 TeV) for vector leptoquarks in a Yang–Mills (minimal-coupling) scenario. In addition, model-independent upper limits are set on the cross section of processes beyond the Standard Model. Expected and observed exclusion contours at the 95% confidence level for the vector third-generation leptoquark signal model, as a function of the mass $m(\text{LQ}_{3}^{\text{v}})$ and the branching fraction $B(\text{LQ}_{3}^{\text{v}} \rightarrow b\tau)$ into a quark and a charged lepton. The plot shows the exclusion contour for vector leptoquarks with additional gauge couplings. The limits are derived from the binned single-tau signal region.

  • Open Access
    Authors: 
    Mroue, Abdul; Boyle, Michael; Lovelace, Geoffrey; Szilagyi, Bela; Pfeiffer, Harald; Zenginoglu, Anil; Kidder, Larry; Taylor, Nicholas; Hemberger, Dan; Scheel, Mark;
    Publisher: Zenodo
    Project: NSERC , NSF | Collaborative Research: D... (1005426), NSF | FRG: Collaborative Resear... (1065438), NSF | Collaborative Research: D... (1005655), NSF | MRI-R2: Acquisition of a ... (0960291), NSF | Research in Black-Hole Ph... (0969111), NSF | Gravitational Radiation a... (1068881)

    Simulation of a black-hole binary system evolved by the SpEC code.