We report the measured transverse momentum ($p_{\rm T}$) spectra of primary charged particles from pp, p-Pb and Pb-Pb collisions at a center-of-mass energy $\sqrt{s_{\rm NN}} = 5.02$ TeV in the kinematic range of $0.15
Transverse momentum spectra of charged particles in PbPb collisions in nine centrality classes.
Transverse momentum spectra of charged particles in PbPb collisions in nine centrality classes.
Transverse momentum spectra of charged particles in pPb collisions.
Measurements of differential cross sections of top quark pair production in association with jets by the ATLAS experiment at the LHC are presented. The measurements are performed as functions of the top quark transverse momentum, the transverse momentum of the top quark-antitop quark system and the out-of-plane transverse momentum using data from $pp$ collisions at $\sqrt{s}=13$ TeV collected by the ATLAS detector at the LHC in 2015 and corresponding to an integrated luminosity of 3.2 fb$^{-1}$. The top quark pair events are selected in the lepton (electron or muon) + jets channel. The measured cross sections, which are compared to several predictions, allow a detailed study of top quark production.
Statistical correlation matrix between |$p_{out}^{t\bar{t}}$| in the 4-jet exclusive configuration and |$p_{out}^{t\bar{t}}$| in the 4-jet exclusive configuration, obtained through the Bootstrap Method.
Statistical correlation matrix between |$p_{out}^{t\bar{t}}$| in the 4-jet exclusive configuration and $p_{T}^{t,had}$ in the 4-jet exclusive configuration, obtained through the Bootstrap Method.
Statistical correlation matrix between |$p_{out}^{t\bar{t}}$| in the 4-jet exclusive configuration and $p_{T}^{t\bar{t}}$ in the 4-jet exclusive configuration, obtained through the Bootstrap Method.
An analysis of the decay $\Lambda_b \to J/\psi(\to\mu^+\mu^-)\Lambda(\to p \pi^-)$ decay is performed to measure the $\Lambda_b$ polarization and three angular parameters in data from pp collisions at $\sqrt{s} =$ 7 and 8 TeV, collected by the CMS experiment at the LHC. The $\Lambda_b$ polarization is measured to be 0.00 $\pm$ 0.06 (stat) $\pm$ 0.06 (syst) and the parity-violating asymmetry parameter is determined to be 0.14 $\pm$ 0.14 (stat) $\pm$ 0.10 (syst). The measurements are compared to various theoretical predictions, including those from perturbative quantum chromodynamics.
The measured values of the angular parameters and the $\Lambda_b$ polarization.
The values of the helicity amplitudes in the decay.
Correlation matrix for the fitted parameters.
Properties of the Higgs boson are measured in the two-photon final state using 36.1 fb$^{-1}$ of proton-proton collision data recorded at $\sqrt{s} = 13$ TeV by the ATLAS experiment at the Large Hadron Collider. Cross-section measurements for the production of a Higgs boson through gluon-gluon fusion, vector-boson fusion, and in association with a vector bosonor a top-quark pair are reported. The signal strength, defined as the ratio of the observed to the expected signal yield, is measured for each of these production processes as well as inclusively. The global signal strength measurement of $0.99 \pm 0.14$ improves on the precision of the ATLAS measurement at $\sqrt{s} = 7$ and 8 TeV by a factor of two. Measurements of gluon-gluon fusion and vector-boson fusion productions yield signal strengths compatible with the Standard Model prediction. Measurements of simplified template cross sections, designed to quantify the different Higgs boson production processes in specific regions of phase space, are reported. The cross section for the production of the Higgs boson decaying to two isolated photons in a fiducial region closely matching the experimental selection of the photons is measured to be $55 \pm 10$ fb, which is in good agreement with the Standard Model prediction of $64 \pm 2$ fb. Furthermore, cross sections in fiducial regions enriched in Higgs boson production in vector-boson fusion or in association with large missing transverse momentum, leptons or top-quark pairs are reported. Differential and double-differential measurements are performed for several variables related to the diphoton kinematics as well as the kinematics and multiplicity of the jets produced in association with a Higgs boson. No significant deviations from a wide array of Standard Model predictions are observed.
Measured differential cross section with associated uncertainties as a function of PT(2GAMMA). Each systematic uncertainty sources is fully uncorrelated with the other sources and fully correlated across bins, except for the background modelling systematics for which an uncorrelated treatment across bins is more appropriate.
Measured differential cross section with associated uncertainties as a function of YRAP(2GAMMA). Each systematic uncertainty sources is fully uncorrelated with the other sources and fully correlated across bins, except for the background modelling systematics for which an uncorrelated treatment across bins is more appropriate.
Measured differential cross section with associated uncertainties as a function of PTTHRUST(2GAMMA). Each systematic uncertainty sources is fully uncorrelated with the other sources and fully correlated across bins, except for the background modelling systematics for which an uncorrelated treatment across bins is more appropriate.
A search is presented for photonic signatures, motivated by generalized models of gauge-mediated supersymmetry breaking. This search makes use of proton-proton collision data at $\sqrt{s}$ = 13 TeV corresponding to an integrated luminosity of 36.1 fb$^{-1}$ recorded by the ATLAS detector at the LHC, and it explores models dominated by both strong and electroweak production of supersymmetric partner states. Experimental signatures incorporating an isolated photon and significant missing transverse momentum are explored. These signatures include events with an additional photon or additional jet activity not associated with any specific underlying quark flavor. No significant excess of events is observed above the Standard Model prediction, and 95% confidence-level upper limits of between 0.083 fb and 0.32 fb are set on the visible cross section of contributions from physics beyond the Standard Model. These results are interpreted in terms of lower limits on the masses of gluinos, squarks, and gauginos in the context of generalized models of gauge-mediated supersymmetry, which reach as high as 2.3 TeV for strongly produced and 1.3 TeV for weakly produced supersymmetric partner pairs.
Distribution of the total visible transverse energy $H_{\mathrm{T}}$ for selected diphoton events, after requiring $\Delta\phi_{\mathrm{min}} (\mathrm{jet}, E_{\mathrm{T}}^{\mathrm{miss}}) > 0.5$ but before application of a requirement on $E_{\mathrm{T}}^{\mathrm{miss}}$ and $\Delta\phi_{\mathrm{min}} (\gamma, E_{\mathrm{T}}^{\mathrm{miss}})$ ($\gamma\gamma$ pre-selection). Also shown are the expected $H_{\mathrm{T}}$ distributions of contributing SM processes as well as those for two points each in the parameter spaces of the gluino-bino and wino-bino GGM models (mass values in GeV). Events outside the range of the displayed region are included in the highest-value bin.
Distribution of $R_{\mathrm{T}}^{4}$ for the sample satisfying all $\mathrm{SR}^{\gamma j}_{L}$ selection criteria except the $R_{\mathrm{T}}^{4}$ requirement itself, but with a relaxed requirement of $E_{\mathrm{T}}^{\mathrm{miss}} > 100$ GeV. Also shown are the expected $R_{\mathrm{T}}^{4}$ distributions of contributing SM processes as well as those for two points in the $m_{\tilde{g}}$-$m_{\tilde{\chi}^{0}_{1}}$ parameter space of the GGM model relevant to the photon+jets analysis (mass values in GeV). The value of the gluino mass arises from the choice $M_3 = 1900$ GeV, while the values of the $\tilde{\chi}^{0}_{1}$ mass arise from the choices $\mu = 400$ and $\mu = 600$ GeV, combined with the constraint that the branching fraction of $\tilde{\chi}^{0}_{1} \to \gamma\tilde{G}$ be 50%. The vertical dashed line and left-pointing arrow shows the region of the $R_{\mathrm{T}}^{4}$ observable selected for inclusion in $\mathrm{SR}^{\gamma j}_{L}$. Uncertainties are shown as hatched bands for the various expected sources of SM background (statistical only) and as error bars for data. The lower panels show the ratio of the data to the SM prediction.
Comparisons between expected and observed content of the validation and signal regions for the diphoton analysis. The uncertainties in the numbers of expected events are the combined statistical and systematic uncertainties. The lower panel shows the pull (difference between observed and expected event counts normalized by the uncertainty) for each region.
A measurement of the inelastic proton-proton cross section with the CMS detector at a center-of-mass energy of $\sqrt{s} =$ 13 TeV is presented. The analysis is based on events with energy deposits in the forward calorimeters, which cover pseudorapidities of -6.6 $< \eta $ 4.1 GeV and/or $M_\mathrm{Y} >$ 13 GeV, where $M_\mathrm{X}$ and $M_\mathrm{Y}$ are the masses of the diffractive dissociation systems at negative and positive pseudorapidities, respectively. The results are compared with those from other experiments as well as to predictions from high-energy hadron-hadron interaction models.
The measured fiducial cross sections. The first bin represents the $\xi > 10^{-6}$ region, while the second bin represents the extended $\xi_{X} > 10^{-7}$ or $\xi_{Y} > 10^{-6}$ result. The first uncertainty is the systematic uncertainty excluding luminosity, the second is the luminosity uncertainty.
A search is reported for heavy resonances decaying into e$\mu$ final states in proton-proton collisions recorded by the CMS experiment at the CERN LHC at $\sqrt{s}=$ 13 TeV, corresponding to an integrated luminosity of 35.9 fb$^{-1}$. The search focuses on resonance masses above 200 GeV. With no evidence found for physics beyond the standard model in the e$\mu$ mass spectrum, upper limits are set at 95% confidence level on the product of the cross section and branching fraction for this lepton-flavor violating signal. Based on these results, resonant $\tau$ sneutrino production in R-parity violating supersymmetric models is excluded for masses below 1.7 TeV, for couplings $\lambda_{132} = \lambda_{231} = \lambda'_{311} = 0.01$. Heavy Z$'$ gauge bosons with lepton-flavor violating transitions are excluded for masses up to 4.4 TeV. The e$\mu$ mass spectrum is also interpreted in terms of non-resonant contributions from quantum black-hole production in models with one to six extra spatial dimensions, and lower mass limits are found between 3.6 and 5.6 TeV. In all interpretations used in this analysis, the results of this search improve previous limits by about 1 TeV. These limits correspond to the most sensitive values obtained at colliders.
Expected upper limits at 95% CL on the product of the signal cross section and branching fraction for the tau sneutrino signal, as a function of the mass of the RPV resonance.
Observed upper limits at 95% CL on the product of the signal cross section and branching fraction for the tau-sneutrino signal, as a function of the mass of the RPV resonance.
Cross section of RPV tau-sneutrino as a function of mass. Cross section includes the branching ratio of tau-sneutrino decaying to $e\mu$.
A measurement of beauty hadron production at mid-rapidity in proton-lead collisions at a nucleon-nucleon centre-of-mass energy $\sqrt{s_{\rm NN}}=5.02$ TeV is presented. The semi-inclusive decay channel of beauty hadrons into J/$\psi$ is considered, where the J/$\psi$ mesons are reconstructed in the dielectron decay channel at mid-rapidity down to transverse momenta of 1.3 GeV/$c$. The ${\rm {b\overline{b}}}$ production cross section at mid-rapidity, ${\rm d}\sigma_{\rm {b\overline{b}}}/{\rm d} y$, and the total cross section extrapolated over full phase space, $\sigma_{\rm {b\overline{b}}}$, are obtained. This measurement is combined with results on inclusive J/$\psi$ production to determine the prompt J/$\psi$ cross sections. The results in p-Pb collisions are then scaled to expectations from pp collisions at the same centre-of-mass energy to derive the nuclear modification factor $R_{\rm pPb}$, and compared to models to study possible nuclear modifications of the production induced by cold nuclear matter effects. $R_{\rm pPb}$ is found to be smaller than unity at low $p_{\rm T}$ for both J/$\psi$ coming from beauty hadron decays and prompt J/$\psi$.
Fraction of non-prompt J/$\psi$ in pp collisions at $\sqrt{s_{NN}}$ = 5.02 TeV for different $p_{\rm T}$ ranges, as determined with a procedure of interpolation from measurments at other energies. It is not a direct measurment.
Fraction of non-prompt J/$\psi$ in pPb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV for different $p_{\rm T}$ ranges.
Fraction of non-prompt J/$\psi$ in pPb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV for different $p_{\rm T}$ ranges.
The transverse momentum balance of pairs of back-to-back b quark jets in PbPb and pp collisions recorded with the CMS detector at the LHC is reported. The center-of-mass energy in both collision systems is 5.02 TeV per nucleon pair. Compared to the pp collision baseline, b quark jets have a larger imbalance in the most central PbPb collisions, as expected from the jet quenching effect. The data are also compared to the corresponding measurement with inclusive dijets. In the most central collisions, the imbalance of b quark dijets is comparable to that of inclusive dijets.
Performance of double b-jet tagging, in terms of b-tagging purity and efficiency
Delta phi distributions of incluisve dijets and b-quark dijets in pp collisions
Delta phi distributions of incluisve dijets and b-quark dijets in central (0-10%) PbPb collisions
A search for $W'$-boson production in the $W' \rightarrow t\bar{b} \rightarrow q\bar{q}' b\bar{b}$ decay channel is presented using 36.1 fb$^{-1}$ of 13 TeV proton-proton collision data collected by the ATLAS detector at the Large Hadron Collider in 2015 and 2016. The search is interpreted in terms of both a left-handed and a right-handed chiral $W'$ boson within the mass range 1-5 TeV. Identification of the hadronically decaying top quark is performed using jet substructure tagging techniques based on a shower deconstruction algorithm. No significant deviation from the Standard Model prediction is observed and the results are expressed as upper limits on the $W' \rightarrow t\bar{b}$ production cross-section times branching ratio as a function of the $W'$-boson mass. These limits exclude $W'$ bosons with right-handed couplings with masses below 3.0 TeV and $W'$ bosons with left-handed couplings with masses below 2.9 TeV, at the 95% confidence level.
Observed and expected 95% CL limits on the right-handed W'-boson cross-section times branching ratio of W' to tb decay as a function of the corresponding W'-boson mass.
Observed and expected 95% CL limits on the left-handed W'-boson cross-section times branching ratio of W' to tb decay as a function of the corresponding W'-boson mass.
Reconstructed mtb distribution in data and for the background after the fit to the data in the signal region SR1. The statistical uncertainty on data points is calculated using assymetric Poisson confidence intervals.
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