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  • 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 acceptance for simplified model with gluino pair production and decays to two quarks and chargino in SR RJR-G3a.

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

    CERN-LHC, ATLAS. A search for a right-handed gauge boson WR, decaying into a boosted right-handed heavy neutrino NR, in the framework of Left-Right Symmetric Models is presented. It is based on data from proton-proton collisions with a centre-of-mass energy of 13 TeV collected by the ATLAS detector at the Large Hadron Collider during the years 2015, 2016 and 2017, corresponding to an integrated luminosity of 80 fb−1. The search is performed separately for electrons and muons in the final state. A distinguishing feature of the search is the use of large-radius jets containing electrons. Selections based on the signal topology result in smaller background compared with to expected signal. No significant deviation from the Standard Model prediction is observed and lower limits are set in the WR and NR mass plane. Mass values of the WR smaller than 3.8-5 TeV are excluded for NR in the mass range 0.1-1.8 TeV. Expected 95% CL exclusion contours in the $(m_{N_R}, m_{W_R})$ plane in the electron channel.

  • 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 gluino pair production and direct decays to two quarks and neutralino in SR RJR-S3a.

  • 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 $\dfrac{\mathrm{d}\sigma}{\mathrm{d}|y(\bar t)|}$ 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, $b-$JES, jet-vertex fraction, $b/\bar{b}$ acceptance, mistag efficiency, $E_{\mathrm{T}}^{\mathrm{miss}}$ 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. 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 acceptance for simplified model with squark pair production and direct decays to a quark and neutralino in SR RJR-S3b.

  • 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 acceptance for simplified model with squark pair production and direct decays to a quark and neutralino in SR Meff-2j-3600.

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

    Measurements are made of differential cross-sections of highly boosted pair-produced top quarks as a function of top-quark and $t\bar{t}$ system kinematic observables using proton--proton collisions at a center-of-mass energy of $\sqrt{s} = 13$ TeV. The data set corresponds to an integrated luminosity of $36.1$ fb$^{-1}$, recorded in 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. Events with two large-radius jets in the final state, one with transverse momentum $p_{\rm T} > 500$ GeV and a second with $p_{\rm T} > 350$ GeV, are used for the measurement. The top-quark candidates are separated from the multijet background using jet substructure information and association with a $b$-tagged jet. The measured spectra are corrected for detector effects to a particle-level fiducial phase space and a parton-level limited phase space, and are compared to several Monte Carlo simulations by means of calculated $\chi^2$ values. The cross-section for $t\bar{t}$ production in the fiducial phase-space region is $292 \pm 7 \rm{(stat)} \pm 76 \rm{(syst)}$ fb, to be compared to the theoretical prediction of $384 \pm 36$ fb. $\Delta \phi(t_{1}, t_{2})$ covariance matrix for the absolute differential cross-section at particle level

  • 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 gluino pair production and direct decays to two quarks and neutralino in SR Meff-2j-1200.

  • 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. Observed and expected background and signal effective mass distributions for SR6j-2600. For signal, a gluino onestep decay model where gluinos have mass of 1705 GeV, the chargino1 has mass of 865 GeV and the neutralino1 has mass of 25 GeV is shown.

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

    CERN-LHC. A search for additional heavy neutral Higgs bosons is performed using a data sample corresponding to an integrated luminosity of 139 fb$^{-1}$ from proton-proton collisions at $\sqrt{s}$ = 13 TeV recorded by the ATLAS detector at the LHC. The 1l1tau_h channel fiducial region is defined as: - 1e+>=1tau_h or 1mu+>=1tau_h - ptLepton > 30 GeV - |etaMuon| < 2.4, |etaEle| < 2.47 (excluding 1.37 < |etaEle| < 1.52) - ptTauVis > 25 GeV - |etaTauVis| < 2.3 (excluding 1.37 < |etaTauVis| < 1.52) - No events with more than 1 electron (ptEle > 15 GeV) or muon (ptMuon > 7 GeV, |etaMuon|<2.5) - If multiple tau_h exist, the leading visible pt one is chosen - l and tau_h opposite electric charge - |DeltaPhi(l,tau_h)| > 2.4 rad - mT(l,MET) < 40 GeV - veto 80 < m(l,tau_h) < 110 in 1e1tau_h channel The 2tau_h channel fiducial region is defined as: - >=2tau_h - ptTauVis > 65 GeV (at least one with ptTauVis > 130 GeV, note that technically, this upper threshold was 85 GeV for ~10% of the data) - No events with an electron or muon, ptLepton > 7 (15) GeV for muons (electrons), |etaMuon| < 2.5, |etaEle| < 2.47 (excluding 1.37 < |etaEle| < 1.52) - If more than two tau_h exist, the two leading visible pt ones are chosen - The two tau_h have opposite electric charge - |DeltaPhi(tau1_h,tau2_h)| > 2.7 rad For Higgs interpretations events entering the fiducial region of each channel are categorised as: - "b-tag: if they contain a b-quark initiated jet (ptJet > 20 GeV, |etaJet|<2.5)" - "b-veto: otherwise" Observed two dimensional likelihood scan of the gluon-gluon fusion cross section times branching fraction, $\sigma(gg\phi)\times B(\phi\to\tau\tau)$, vs the b-associated production times branching fraction, $\sigma(bb\phi)\times B(\phi\to\tau\tau)$ for the scalar boson mass ($m_\phi$) indicated in the table. For each mass, 10000 points are scanned. At each point $\Delta(\mathrm{NLL})$ is calculated, defined as the negative-log-likelihood (NLL) of the conditional fit with $\sigma(gg\phi)$ and $\sigma(bb\phi)$ fixed to their values at the point and with the minimum NLL value at any point subtracted. The best-fit point and the preferred 68% and 95% boundaries are found at $2\Delta(\mathrm{NLL})$ values of 0.0, 2.30 and 5.90, respectively. The value of $2\Delta(\mathrm{NLL})$ for 1500 GeV signal mass point is shown in the HEPData table.

search
Include:
The following results are related to Canada. Are you interested to view more results? Visit OpenAIRE - Explore.
4,590 Research products, page 1 of 459
  • 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 acceptance for simplified model with gluino pair production and decays to two quarks and chargino in SR RJR-G3a.

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

    CERN-LHC, ATLAS. A search for a right-handed gauge boson WR, decaying into a boosted right-handed heavy neutrino NR, in the framework of Left-Right Symmetric Models is presented. It is based on data from proton-proton collisions with a centre-of-mass energy of 13 TeV collected by the ATLAS detector at the Large Hadron Collider during the years 2015, 2016 and 2017, corresponding to an integrated luminosity of 80 fb−1. The search is performed separately for electrons and muons in the final state. A distinguishing feature of the search is the use of large-radius jets containing electrons. Selections based on the signal topology result in smaller background compared with to expected signal. No significant deviation from the Standard Model prediction is observed and lower limits are set in the WR and NR mass plane. Mass values of the WR smaller than 3.8-5 TeV are excluded for NR in the mass range 0.1-1.8 TeV. Expected 95% CL exclusion contours in the $(m_{N_R}, m_{W_R})$ plane in the electron channel.

  • 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 gluino pair production and direct decays to two quarks and neutralino in SR RJR-S3a.

  • 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 $\dfrac{\mathrm{d}\sigma}{\mathrm{d}|y(\bar t)|}$ 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, $b-$JES, jet-vertex fraction, $b/\bar{b}$ acceptance, mistag efficiency, $E_{\mathrm{T}}^{\mathrm{miss}}$ 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. 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 acceptance for simplified model with squark pair production and direct decays to a quark and neutralino in SR RJR-S3b.

  • 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 acceptance for simplified model with squark pair production and direct decays to a quark and neutralino in SR Meff-2j-3600.

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

    Measurements are made of differential cross-sections of highly boosted pair-produced top quarks as a function of top-quark and $t\bar{t}$ system kinematic observables using proton--proton collisions at a center-of-mass energy of $\sqrt{s} = 13$ TeV. The data set corresponds to an integrated luminosity of $36.1$ fb$^{-1}$, recorded in 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. Events with two large-radius jets in the final state, one with transverse momentum $p_{\rm T} > 500$ GeV and a second with $p_{\rm T} > 350$ GeV, are used for the measurement. The top-quark candidates are separated from the multijet background using jet substructure information and association with a $b$-tagged jet. The measured spectra are corrected for detector effects to a particle-level fiducial phase space and a parton-level limited phase space, and are compared to several Monte Carlo simulations by means of calculated $\chi^2$ values. The cross-section for $t\bar{t}$ production in the fiducial phase-space region is $292 \pm 7 \rm{(stat)} \pm 76 \rm{(syst)}$ fb, to be compared to the theoretical prediction of $384 \pm 36$ fb. $\Delta \phi(t_{1}, t_{2})$ covariance matrix for the absolute differential cross-section at particle level

  • 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 gluino pair production and direct decays to two quarks and neutralino in SR Meff-2j-1200.

  • 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. Observed and expected background and signal effective mass distributions for SR6j-2600. For signal, a gluino onestep decay model where gluinos have mass of 1705 GeV, the chargino1 has mass of 865 GeV and the neutralino1 has mass of 25 GeV is shown.

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

    CERN-LHC. A search for additional heavy neutral Higgs bosons is performed using a data sample corresponding to an integrated luminosity of 139 fb$^{-1}$ from proton-proton collisions at $\sqrt{s}$ = 13 TeV recorded by the ATLAS detector at the LHC. The 1l1tau_h channel fiducial region is defined as: - 1e+>=1tau_h or 1mu+>=1tau_h - ptLepton > 30 GeV - |etaMuon| < 2.4, |etaEle| < 2.47 (excluding 1.37 < |etaEle| < 1.52) - ptTauVis > 25 GeV - |etaTauVis| < 2.3 (excluding 1.37 < |etaTauVis| < 1.52) - No events with more than 1 electron (ptEle > 15 GeV) or muon (ptMuon > 7 GeV, |etaMuon|<2.5) - If multiple tau_h exist, the leading visible pt one is chosen - l and tau_h opposite electric charge - |DeltaPhi(l,tau_h)| > 2.4 rad - mT(l,MET) < 40 GeV - veto 80 < m(l,tau_h) < 110 in 1e1tau_h channel The 2tau_h channel fiducial region is defined as: - >=2tau_h - ptTauVis > 65 GeV (at least one with ptTauVis > 130 GeV, note that technically, this upper threshold was 85 GeV for ~10% of the data) - No events with an electron or muon, ptLepton > 7 (15) GeV for muons (electrons), |etaMuon| < 2.5, |etaEle| < 2.47 (excluding 1.37 < |etaEle| < 1.52) - If more than two tau_h exist, the two leading visible pt ones are chosen - The two tau_h have opposite electric charge - |DeltaPhi(tau1_h,tau2_h)| > 2.7 rad For Higgs interpretations events entering the fiducial region of each channel are categorised as: - "b-tag: if they contain a b-quark initiated jet (ptJet > 20 GeV, |etaJet|<2.5)" - "b-veto: otherwise" Observed two dimensional likelihood scan of the gluon-gluon fusion cross section times branching fraction, $\sigma(gg\phi)\times B(\phi\to\tau\tau)$, vs the b-associated production times branching fraction, $\sigma(bb\phi)\times B(\phi\to\tau\tau)$ for the scalar boson mass ($m_\phi$) indicated in the table. For each mass, 10000 points are scanned. At each point $\Delta(\mathrm{NLL})$ is calculated, defined as the negative-log-likelihood (NLL) of the conditional fit with $\sigma(gg\phi)$ and $\sigma(bb\phi)$ fixed to their values at the point and with the minimum NLL value at any point subtracted. The best-fit point and the preferred 68% and 95% boundaries are found at $2\Delta(\mathrm{NLL})$ values of 0.0, 2.30 and 5.90, respectively. The value of $2\Delta(\mathrm{NLL})$ for 1500 GeV signal mass point is shown in the HEPData table.