Dijet angular distributions are measured over a wide range of dijet invariant masses in pp collisions at sqrt(s) = 7 TeV, at the CERN LHC. The event sample, recorded with the CMS detector, corresponds to an integrated luminosity of 36 inverse picobarns. The data are found to be in good agreement with the predictions of perturbative QCD, and yield no evidence of quark compositeness. With a modified frequentist approach, a lower limit on the contact interaction scale for left-handed quarks of Lambda = 5.6 TeV (6.7 TeV) for destructive (constructive) interference is obtained at the 95% confidence level.
We have measured the dijet angular distribution in $\sqrt{s}$=1.8 TeV $p\bar{p}$ collisions using the D0 detector. Order $α^{3}_{s}$ QCD predictions are in good agreement with the data. At 95% confidence the data exclude models of quark compositeness in which the contact interaction scale is below 2 TeV.
We present the first measurement of dijet angular distributions in ppbar collisions at sqrt{s}=1.96TeV at the Fermilab Tevatron Collider. The measurement is based on a dataset corresponding to an integrated luminosity of up to 0.7fb-1 collected with the D0 detector. Dijet angular distributions have been measured over a range of dijet masses, from 0.25TeV to above 1.1TeV. The data are in good agreement with the predictions of perturbative QCD and are used to constrain new physics models including quark compositeness, large extra dimensions, and TeV-1 scale extra dimensions. For all models we se…
Using the DZero detector at the 1.8 TeV pbarp Fermilab Tevatron collider, we have measured the inclusive dijet mass spectrum in the central pseudorapidity region |eta_jet| < 1.0 for dijet masses greater than 200 Gev/c^2. We have also measured the ratio of spectra sigma(|eta_jet| < 0.5)/sigma(0.5 < |eta_jet| < 1.0). The order alpha_s^3 QCD predictions are in good agreement with the data and we rule out models of quark compositeness with a contact interaction scale < 2.4 TeV at the 95% confidence level.
A search for quark compositeness using dijet angular distributions from pp collisions at sqrt(s) = 7 TeV is presented. The search has been carried out using a data sample corresponding to an integrated luminosity of 2.2 inverse femtobarns, recorded by the CMS experiment at the LHC. Normalized dijet angular distributions have been measured for dijet invariant masses from 0.4 TeV to above 3 TeV and compared with a variety of contact interaction models, including those which take into account the effects of next-to-leading-order QCD corrections. The data are found to be in agreement with the pred…
A search for quark compositeness in the form of quark contact interactions, based on hadronic jet pairs (dijets) produced in proton-proton collisions at sqrt(s)=7 TeV, is described. The data sample of the study corresponds to an integrated luminosity of 2.9 inverse picobarns collected with the CMS detector at the LHC. The dijet centrality ratio, which quantifies the angular distribution of the dijets, is measured as a function of the invariant mass of the dijet system and is found to agree with the predictions of the Standard Model. A statistical analysis of the data provides a lower limit on …
Quark-quark and quark-lepton searches for compositenss at the Fermilab Tevatron are summarized. These are of the contact-interaction variety where sqrt(s-hat) < the hypothesized mass scales, Lambda. Tevatron experiments limit a variety of compositeness phenomena in the range from 1.9 to 8.3 TeV. These limits result from measurements of: the Ht spectrum (D0), dijet mass (D0), dijet angular distribution (CDF, D0), drell-yan production (CDF, D0), and the Neutral Current to Charged Current ratio (CCFR/NuTeV).
Dijet angular distributions from the first proton-proton collisions at 7 TeV have been measured with the ATLAS detector at the LHC. The dataset used corresponds to a total integrated luminosity of 61 $\pm$ 7 nb$^{-1}$. Comparing the distributions with Monte Carlo based QCD predictions shows good agreement between data and QCD. The distributions are used to set limits on the existence of quark compositeness.
Using recent D0 data on the dijet mass spectrum, we present a limit on flavor-universal colorons. At 95% CL we find Mc/cot(theta) > 837 GeV. We discuss the implications of this limit for models of quark compositeness, non-standard gluon interactions, and dynamical electroweak symmetry breaking. In addition, we place a lower bound Lambda_A8 > 2.1 TeV on the scale of color-octet axial-vector contact interactions among quarks which could arise in models of quark compositeness.
Recent searches for leptoquark production and compositeness in p-anti-p collisions at sqrt{s}=1.96 TeV are presented using data samples with integrated luminosities up to 4 fb^{-1} recorded with the D0 and CDF detectors at the Tevatron collider.
We present searches for dijet and ttbar mass resonances using between 0.68 and 2.1 fb-1 of Tevatron Run II data collected by the CDF and D0 detectors. No evidence of new physics is found, and 95% C.L. limits are set on a number of new physics hypotheses, such as excited quark, Randal-Sundrum graviton, Z', W', color-octet technirho, axigluon and flavor-universal coloron, E6 diquark, quark compositeness, ADD and TeV-1-sized LED, massive gluon.
A study is presented of the sensitivity of potential future $pp$ colliders to quark compositeness. The analysis uses normalized dijet angular distributions compared to expectations from leading-order contact interaction models.
We present the exact next-to-leading order (NLO) QCD corrections to dijet production at the LHC via quark contact interactions, with different color and chiral structures induced from new physics. Following the recent analysis of quark compositeness search at the LHC, we find that the NLO QCD corrections can lower the dijet cross sections by several tens percent, depending on the theory parameters and the selected kinematic regions, and reduce the dependence of the cross sections on factorization and renormalization scales. We also calculate the renormalization group (RG) improved NLO cross se…
We make a Monte Carlo study on compositeness of first generation quarks and leptons using the Drell-Yan distribution in the high dielectron mass region at the Tevatron and LHC energies. The current experimental lower limits on the compositeness scale, Λ, vary from 2.5 to 6.1 TeV. In the present analysis, we assume that there will be no deviation of the dielectron mass spectrum from Standard Model prediction at center of mass energy 2 TeV (Tevatron) and 14 TeV (LHC). We then find that in the LL, RR, RL and LR chirality channels of the quark-electron currents, it is possible to extend the lower …
Events in PbarP collisions at sqrt(s)=1.8 TeV with total transverse energy exceeding 500 GeV are used to set limits on quark substructure. The data are consistent with next-to-leading order QCD calculations. We set a lower limit of 2.0 TeV at 95% confidence on the energy scale Lambda_LL for compositeness in quarks, assuming a model with a left-left isoscalar contact interaction term. The limits on Lambda_LL are found to be insensitive to the sign of the interference term in the Lagrangian.
Dijet angular distributions from the first LHC pp collisions at center-of-mass energy sqrt(s) = 7 TeV have been measured with the ATLAS detector. The dataset used for this analysis represents an integrated luminosity of 3.1 pb-1. Dijet $χ$ distributions and centrality ratios have been measured up to dijet masses of 2.8 TeV, and found to be in good agreement with Standard Model predictions. Analysis of the $χ$ distributions excludes quark contact interactions with a compositeness scale $Λ$ below 3.4 TeV, at 95% confidence level, significantly exceeding previous limits.
A measurement of the double-differential inclusive dijet production cross section in proton-proton collisions at \sqrt{s}= 7 TeV is presented as a function of the dijet invariant mass and jet rapidity. The data correspond to an integrated luminosity of 36 pb^{-1}, recorded with the CMS detector at the LHC in 2010. The measurement covers the dijet mass range 0.2 TeV to 3.5 TeV and jet rapidities up to |y|=2.5. It is found to be in good agreement with next-to-leading-order QCD predictions.
A measurement of the double-differential inclusive dijet production cross section in proton-proton collisions at sqrt(s)=7 TeV is presented as a function of the dijet invariant mass and jet rapidity. The data correspond to an integrated luminosity of 36 inverse picobarns, recorded with the CMS detector at the LHC. The measurement covers the dijet mass range 0.2 TeV to 3.5 TeV and jet rapidities up to |y|=2.5. It is found to be in good agreement with next-to-leading-order QCD predictions.
Measurements of dijet azimuthal decorrelations in pp collisions at sqrt(s) = 7 TeV using the CMS detector at the CERN LHC are presented. The analysis is based on an inclusive dijet event sample corresponding to an integrated luminosity of 2.9 inverse picobarns. The results are compared to predictions from perturbative QCD calculations and various Monte Carlo event generators. The dijet azimuthal distributions are found to be sensitive to initial-state gluon radiation.
We present searches for quark-lepton compositeness and a heavy W' boson at high electron-neutrino transverse mass. We use ~110/pb of data collected in p-pbar collisions at sqrt(s) = 1.8 TeV by the CDF collaboration during 1992--95. The data are consistent with standard model expectations. Limits are set on the quark-lepton compositeness scale Lambda and the ratio of partial cross sections sigma (W' -> e nu) / sigma (W -> e nu). The cross section ratio is used to obtain a lower limit on the mass of a W' boson with standard model couplings. We exclude Lambda < 2.81 TeV and a W' boson with mass b…
We present evidence for diffractive exclusive dijet production with an invariant dijet mass greater than 100 GeV in data collected with the D0 experiment at the Fermilab Tevatron Collider. A discriminant based on calorimeter information is used to measure a significant number of events with little energy (typically less than 10 GeV) outside the dijet system, consistent with the diffractive exclusive dijet production topology. The probability for these events to be explained by other dijet production processes is $2 \times 10^{-5}$, corresponding to a 4.1 standard deviation significance.
We present a measurement of the Drell-Yan cross section at high dielectron invariant mass using 120/pb of data collected in pbar-p collisions at sqrt(s) = 1.8 TeV by the D0 collaboration during 1992-96. No deviation from standard model expectations is observed. We use the data to set limits on the energy scale of quark-electron compositeness with common constituents. The 95% confidence level lower limits on the compositeness scale vary between 3.3 TeV and 6.1 TeV depending on the assumed form of the effective contact interaction.
Measurements of the inclusive jet cross section and the dijet angular distribution using data from the Tevatron are presented. Comparisons to NLO QCD show good agreement below 250 GeV, but CDF data show an excess at higher ET; qualitative agreement is seen between the CDF and DO cross sections. Analysis of the dijet angular distributions exclude quark compositeness below 2.1 TeV.
The differential cross section measurement for dijet production at proton-proton collisions at $\sqrt{s}=7$ TeV is presented as a function of an approximation for the fractional momentum loss of the scattered proton ($\tildeξ$), an useful observable to distinguish model predictions of diffractive and nondiffractive components. The data was collected by the CMS detector at low instantaneous luminosity runs at LHC, corresponding to an integrated luminosity of $2.7 {\rm nb}^{-1}$. This is the first observation of single diffractive dijets at LHC.
We present a study of the dijet invariant mass spectrum in events with two jets produced in association with a W boson in data corresponding to an integrated luminosity of 4.3 fb^-1 collected with the D0 detector at sqrt{s} =1.96 TeV. We find no evidence for anomalous resonant dijet production and derive upper limits on the production cross section of an anomalous dijet resonance recently reported by the CDF Collaboration, investigating the range of dijet invariant mass from 110 to 170 GeV/c^2. The probability of the D0 data being consistent with the presence of a dijet resonance with 4 pb pro…
A search for narrow resonances with a mass of at least 1 TeV in the dijet mass spectrum is performed using pp collisions at sqrt(s)=7 TeV corresponding to an integrated luminosity of 1 inverse femtobarn, collected by the CMS experiment at the LHC. No resonances are observed. Upper limits at the 95% confidence level are presented on the product of the resonance cross section, branching fraction into dijets, and acceptance, separately for decays into quark-quark, quark-gluon, and gluon-gluon pairs. The data exclude new particles predicted in the following models at the 95% confidence level: stri…
We use a sample of diphoton + dijet events to measure the effective cross section of double parton interactions, which is found to be $σ_{\rm eff} = 19.3$ $\pm$ $1.4({\rm stat})$ $\pm$ $7.8({\rm syst})$ mb. The sample was collected by the D0 detector at the Fermilab Tevatron collider in $p\bar{p}$ collisions at $\sqrt{s} = 1.96$ TeV and corresponds to an integrated luminosity of 8.7 fb$^{-1}$.
At hadron colliders, new massive particles can be searched for by the observation of high tranverse momentum objects forming high-mass resonances. Searches for additional massive vector bosons (W',Z'), Randall-Sundrum gravitons and sneutrinos in R-parity violating scenarios are performed in dilepton, dijets and diboson final states. The most recent results from the CDF and D0 experiments at the Tevatron are presented corresponding to integrated luminosities between 1 and 4 fb^{-1}.
Invariant mass distributions of jet pairs (dijets) produced in LHC proton-proton collisions at a centre-of-mass energy sqrt(s)=7 TeV have been studied using a data set corresponding to an integrated luminosity of 1.0 fb^-1 recorded in 2011 by ATLAS. Dijet masses up to ~4 TeV are observed in the data, and no evidence of resonance production over background is found. Limits are set at 95% CL for several new physics hypotheses: excited quarks are excluded for masses below 2.99 TeV, axigluons are excluded for masses below 3.32 TeV, and colour octet scalar resonances are excluded for masses below 1…
A search for new interactions and resonances produced in LHC proton-proton (pp) collisions at a centre-of-mass energy sqrt(s)= 7 TeV has been performed with the ATLAS detector. Using a data set with an integrated luminosity of 36 pb-1 dijet mass and angular distributions have been measured up to dijet masses of \sim 3.5 TeV and found to be in good agreement with Standard Model predictions. This analysis sets limits at 95% C.L. on various models for new physics: an excited quark is excluded with mass between 0.60 and 2.64 TeV, an axigluon hypothesis is excluded for axigluon masses between 0.60 …
A search is presented for narrow resonances decaying to dijet final states in proton-proton collisions at sqrt(s) = 13 TeV using data corresponding to an integrated luminosity of 12.9 inverse femtobarns. The dijet mass spectrum is well described by a smooth parameterization and no significant evidence for the production of new particles is observed. Upper limits at 95% confidence level are reported on the production cross section for narrow resonances with masses above 0.6 TeV. In the context of specific models, the limits exclude string resonances with masses below 7.4 TeV, scalar diquarks be…
High energy jet distributions measured since 1992 at the Fermilab Tevatron proton--antiproton collider are presented and compared to theoretical predictions. The statistical uncertainties on these measurements are significantly reduced relative to previous results. The systematic uncertainties are comparable in size to the uncertainty in the theoretical predictions. Although some discrepancies between theory and measurements are noted, the inclusive jet and dijet cross sections can be described by quantum chromodynamics. Prospects for reducing the uncertainty in the theoretical predictions by …
The inclusive dijet production double differential cross section as a function of the dijet invariant mass and of the largest absolute rapidity of the two jets with the largest transverse momentum in an event is measured in proton anti-proton collisions at sqrt{s} = 1.96 TeV using 0.7 fb^{-1} integrated luminosity collected with the D0 detector at the Fermilab Tevatron Collider. The measurement is performed in six rapidity regions up to a maximum rapidity of 2.4. Next-to-leading order perturbative QCD predictions are found to be in agreement with the data.
Dijet events produced in LHC proton--proton collisions at a center-of-mass energy $\sqrt{s}=8$ TeV are studied with the ATLAS detector using the full 2012 data set, with an integrated luminosity of 20.3 fb$^{-1}$. Dijet masses up to about 4.5 TeV are probed. No resonance-like features are observed in the dijet mass spectrum. Limits on the cross section times acceptance are set at the 95% credibility level for various hypotheses of new phenomena in terms of mass or energy scale, as appropriate. This analysis excludes excited quarks with a mass below 4.09 TeV, color-octet scalars with a mass bel…
A search for narrow resonances in the dijet mass spectrum is performed using data corresponding to an integrated luminosity of 2.9 inverse pb collected by the CMS experiment at the LHC. Upper limits at the 95% confidence level (CL) are presented on the product of the resonance cross section, branching fraction into dijets, and acceptance, separately for decays into quark-quark, quark-gluon, or gluon-gluon pairs. The data exclude new particles predicted in the following models at the 95% CL: string resonances, with mass less than 2.50 TeV, excited quarks, with mass less than 1.58 TeV, and axigl…
Mass and angular distributions of dijets produced in LHC proton-proton collisions at a centre-of-mass energy sqrt(s)=7 TeV have been studied with the ATLAS detector using the full 2011 data set with an integrated luminosity of 4.8/fb. Dijet masses up to 4.0 TeV have been probed. No resonance-like features have been observed in the dijet mass spectrum, and all angular distributions are consistent with the predictions of QCD. Exclusion limits on six hypotheses of new phenomena have been set at 95% CL in terms of mass or energy scale, as appropriate. These hypotheses include excited quarks below …
A search for the pair production of a heavy, narrow resonance decaying into two jets has been performed using events collected in sqrt(s) = 7 TeV pp collisions with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 5.0 inverse femtobarns. Events are selected with at least four jets and two dijet combinations with similar dijet mass. No resonances are found in the dijet mass spectrum. The upper limit at 95% confidence level on the product of the resonance pair production cross section, the branching fractions into dijets, and the acceptance varies from 0.22…
The cross section for dijet production in pp collisions at sqrt(s) = 7 TeV is presented as a function of xi, a variable that approximates the fractional momentum loss of the scattered proton in single-diffractive events. The analysis is based on an integrated luminosity of 2.7 inverse nanobarns collected with the CMS detector at the LHC at low instantaneous luminosities, and uses events with jet transverse momentum of at least 20 GeV. The dijet cross section results are compared to the predictions of diffractive and nondiffractive models. The low-xi data show a significant contribution from di…
A search for narrow resonances and quantum black holes is performed in inclusive and b-tagged dijet mass spectra measured with the CMS detector at the LHC. The data set corresponds to 5 inverse femtobarns of integrated luminosity collected in pp collisions at sqrt(s) = 7 TeV. No narrow resonances or quantum black holes are observed. Model-independent upper limits at the 95% confidence level are obtained on the product of the cross section, branching fraction into dijets, and acceptance for three scenarios: decay into quark-quark, quark-gluon, and gluon-gluon pairs. Specific lower limits are se…
A search for narrow resonances in proton-proton collisions at sqrt(s) = 13 TeV is presented. The invariant mass distribution of the two leading jets is measured with the CMS detector using a data set corresponding to an integrated luminosity of 2.4 inverse femtobarns. The highest observed dijet mass is 6.1 TeV. The distribution is smooth and no evidence for resonant particles is observed. Upper limits at 95% confidence level are set on the production cross section for narrow resonances with masses above 1.5 TeV. When interpreted in the context of specific models, the limits exclude string reso…
We present results of a signature-based search for new physics using a dijet plus missing transverse energy data sample collected in 2 fb-1 of p-pbar collisions at sqrt(s) = 1.96 TeV with the CDF II detector at the Fermilab Tevatron. We observe no significant event excess with respect to the standard model prediction and extract a 95% C.L. upper limit on the cross section times acceptance for a potential contribution from a non-standard model process. Based on this limit the mass of a first or second generation scalar leptoquark is constrained to be above 187 GeV/c^2.
We present the first combined measurement of the rapidity and transverse momentum dependence of dijet azimuthal decorrelations, based on the recently proposed quantity $R_{Δϕ}$. The variable $R_{Δϕ}$ measures the fraction of the inclusive dijet events in which the azimuthal separation of the two jets with the highest transverse momenta is less than a specified value for the parameter $Δϕ_{\rm max}$. The quantity $R_{Δϕ}$ is measured in $p\bar{p}$ collisions at $\sqrt{s}=1.96\,$TeV, as a function of the dijet rapidity interval, the total scalar transverse momentum, and $Δϕ_{\rm max}$. The measu…
We present a search for new particles whose decays produce two jets (dijets) using proton-antiproton collision data corresponding to an integrated luminosity of 1.13 fb-1 collected with the CDF II detector. The measured dijet mass spectrum is found to be consistent with next-to-leading-order perturbative QCD predictions, and no significant evidence of new particles is found. We set upper limits at the 95% confidence level on cross sections times the branching fraction for the production of new particles decaying into dijets with both jets having a rapidity magnitude |y| < 1. These limits are u…
Correlations in the azimuthal angle between the two largest transverse momentum jets have been measured using the D0 detector in pp-bar collisions at a center-of-mass energy sqrt(s)=1.96 TeV. The analysis is based on an inclusive dijet event sample in the central rapidity region corresponding to an integrated luminosity of 150 pb-1. Azimuthal correlations are stronger at larger transverse momenta. These are well-described in perturbative QCD at next-to-leading order in the strong coupling constant, except at large azimuthal differences where soft effects are significant.
A search is presented for quark contact interactions and extra spatial dimensions in proton-proton collisions at sqrt(s) = 8 TeV using dijet angular distributions. The search is based on a data set corresponding to an integrated luminosity of 19.7 inverse femtobarns collected by the CMS detector at the CERN LHC. Dijet angular distributions are found to be in agreement with the perturbative QCD predictions that include electroweak corrections. Limits on the contact interaction scale from a variety of models at next-to-leading order in QCD corrections are obtained. A benchmark model in which onl…
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; m…
A search has been made for massive resonances decaying into a quark and a vector boson, qW or qZ, or a pair of vector bosons, WW, WZ, or ZZ, where each vector boson decays to hadronic final states. This search is based on a data sample corresponding to an integrated luminosity of 5.0 inverse femtobarns of proton-proton collisions collected in the CMS experiment at the LHC in 2011 at a center-of-mass energy of 7 TeV. For sufficiently heavy resonances the decay products of each vector boson are merged into a single jet, and the event effectively has a dijet topology. The background from QCD dije…
Azimuthal decorrelations between the two central jets with the largest transverse momenta are sensitive to the dynamics of events with multiple jets. We present a measurement of the normalized differential cross section based on the full dataset (L=36/pb) acquired by the ATLAS detector during the 2010 sqrt(s)=7 TeV proton-proton run of the LHC. The measured distributions include jets with transverse momenta up to 1.3 TeV, probing perturbative QCD in a high energy regime.
A search for dijet resonances in events with at least one isolated charged lepton is performed using $139~{\text{fb}}^{-1}$ of $\sqrt{s}=13$ TeV proton-proton collision data recorded by the ATLAS detector at the LHC. The dijet invariant-mass ($m_{jj}$) distribution constructed from events with at least one isolated electron or muon is searched in the region $0.22 < m_{jj} < 6.3$ TeV for excesses above a smoothly falling background from Standard Model processes. Triggering based on the presence of a lepton in the event reduces limitations imposed by minimum transverse momentum thresholds for tr…
We report an investigation of the invariant mass spectrum of the two jets with highest transverse momentum in pp to W+2-jet and W+3-jet events to look for resonant enhancements. The data sample corresponds to an integrated luminosity of 5.0 inverse femtobarns collected with the CMS detector at sqrt(s) = 7 TeV. We find no evidence for the anomalous structure reported by the CDF Collaboration, and establish an upper limit of 5.0 pb at 95% confidence level on the production cross section for a generic Gaussian signal with mass near 150 GeV. Additionally, we exclude two theoretical models that pre…
Inclusive jet and dijet cross sections have been measured in proton-proton collisions at a centre-of-mass energy of 7 TeV using the ATLAS detector at the Large Hadron Collider. The cross sections were measured using jets clustered with the anti-kT algorithm with parameters R=0.4 and R=0.6. These measurements are based on the 2010 data sample, consisting of a total integrated luminosity of 37 inverse picobarns. Inclusive jet double-differential cross sections are presented as a function of jet transverse momentum, in bins of jet rapidity. Dijet double-differential cross sections are studied as …
A measurement of jet activity in the rapidity interval bounded by a dijet system is performed using pp collisions at 7 TeV recorded by the ATLAS detector in 2010. The data are compared to LO predictions from PYTHIA, HERWIG++ and ALPGEN event generators. The data are also compared to NLO parton shower prediction from POWHEG, when interfaced to PYTHIA or HERWIG parton shower, and all order resummation prediction from HEJ. In most of the phase-space regions presented, the experimental uncertainty is much smaller than the spread of LO Monte Carlo event generator predictions. In general, POWHEG+PYT…
Results are presented of a search for the production of new particles decaying to pairs of partons (quarks, antiquarks, or gluons), in the dijet mass spectrum in proton-proton collisions at sqrt(s) = 8 TeV. The data sample corresponds to an integrated luminosity of 4.0 inverse femtobarns, collected with the CMS detector at the LHC in 2012. No significant evidence for narrow resonance production is observed. Upper limits are set at the 95% confidence level on the production cross section of hypothetical new particles decaying to quark-quark, quark-gluon, or gluon-gluon final states. These limit…
Inclusive jet and dijet cross-sections are measured in proton-proton collisions at a centre-of-mass energy of 13 TeV. The measurement uses a dataset with an integrated luminosity of 3.2 fb$^{-1}$ recorded in 2015 with the ATLAS detector at the Large Hadron Collider. Jets are identified using the anti-${k_t}$ algorithm with a radius parameter value of $R=0.4$. The inclusive jet cross-sections are measured double-differentially as a function of the jet transverse momentum, covering the range from 100 GeV to 3.5 TeV, and the absolute jet rapidity up to $|y|=3$. The double-differential dijet produ…
The dijet production cross section for jets containing a $b$-hadron ($b$-jets) has been measured in proton-proton collisions with a centre-of-mass energy of $\sqrt{s} = 7$ TeV, using the ATLAS detector at the LHC. The data used correspond to an integrated luminosity of 4.2 fb$^{-1}$. The cross section is measured for events with two identified $b$-jets with a transverse momentum $p_T > 20$ GeV and a minimum separation in the $η$-$ϕ$ plane of $ΔR = 0.4$. At least one of the jets in the event is required to have $p_T > 270$ GeV. The cross section is measured differentially as a function of dijet…
Additional jet activity in dijet events is measured using $pp$ collisions at ATLAS at a centre-of-mass energy of 7 TeV, for jets reconstructed using the anti-kt algorithm with radius parameter R=0.6. This is done using variables such as the fraction of dijet events without an additional jet in the rapidity interval bounded by the dijet subsystem and correlations between the azimuthal angles of the dijets. They are presented, both with and without a veto on additional jet activity in the rapidity interval, as a function of the mean transverse momentum of the dijets and of the rapidity interval …
Search for electroweak-scale dijet resonances using trigger-level analysis with the ATLAS detector in $132$ fb$^{-1}$ of $pp$ collisions at $\sqrt{s} = 13$ TeV
