The fiducial cross section for $\Upsilon$(1S) pair production in proton-proton collisions at a center-of-mass energy of 13 TeV in the region where both $\Upsilon$(1S) mesons have an absolute rapidity below 2.0 is measured to be 79 $\pm$ 11 (stat) $\pm$ 6 (syst) $\pm$ 3 ($\mathcal{B}$) pb assuming the mesons are produced unpolarized. The last uncertainty corresponds to the uncertainty in the $\Upsilon$(1S) meson dimuon branching fraction. The measurement is performed in the final state with four muons using proton-proton collision data collected in 2016 by the CMS experiment at the LHC, corresponding to an integrated luminosity of 35.9 fb$^{-1}$. This process serves as a standard model reference in a search for narrow resonances decaying to $\Upsilon$(1S)$\mu^+\mu^-$ in the same final state. Such a resonance could indicate the existence of a tetraquark that is a bound state of two b quarks and two $\bar{\mathrm{b}}$ antiquarks. The tetraquark search is performed for masses in the vicinity of four times the bottom quark mass, between 17.5 and 19.5 GeV, while a generic search for other resonances is performed for masses between 16.5 and 27 GeV. No significant excess of events compatible with a narrow resonance is observed in the data. Limits on the production cross section times branching fraction to four muons via an intermediate $\Upsilon$(1S) resonance are set as a function of the resonance mass.
The fiducial cross section measured in bins of the absolute rapidity difference between the mesons for events in the fiducial region with 2 Y(1S) with absolute rapidity less than 2.0.
The fiducial cross section measured in bins of the invariant mass of the two mesons for events in the fiducial region with 2 Y(1S) with absolute rapidity less than 2.0.
The fiducial cross section measured in bins of the transverse momentum of the meson pair for events in the fiducial region with 2 Y(1S) with absolute rapidity less than 2.0.
A measurement is presented of differential cross sections for $t$-channel single top quark and antiquark production in proton-proton collisions at a centre-of-mass energy of 13 TeV by the CMS experiment at the LHC. From a data set corresponding to an integrated luminosity of 35.9 fb$^{-1}$, events containing one muon or electron and two or three jets are analysed. The cross section is measured as a function of the top quark transverse momentum ($p_\mathrm{T}$), rapidity, and polarisation angle, the charged lepton $p_\mathrm{T}$ and rapidity, and the $p_\mathrm{T}$ of the W boson from the top quark decay. In addition, the charge ratio is measured differentially as a function of the top quark, charged lepton, and W boson kinematic observables. The results are found to be in agreement with standard model predictions using various next-to-leading-order event generators and sets of parton distribution functions. Additionally, the spin asymmetry, sensitive to the top quark polarisation, is determined from the differential distribution of the polarisation angle at parton level to be 0.440 $\pm$ 0.070, in agreement with the standard model prediction.
Differential absolute cross section as a function of the parton-level top quark $p_\textrm{T}$
Covariance of the differential absolute cross section as a function of the parton-level top quark $p_\textrm{T}$
Differential absolute cross section as a function of the parton-level top quark rapidity
Measurements are presented of associated production of a W boson and a charm quark (W+c) in proton-proton collisions at a center-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 35.7 fb$^{-1}$ collected by the CMS experiment at the CERN LHC. The W bosons are identified by their decay into a muon and a neutrino. The charm quarks are tagged via the full reconstruction of D$^*$(2010)$^\pm$ mesons that decay via D$^*$(2010)$^\pm \to$ D$^0$ + $\pi^\pm \to$ K$^{\mp}$ + $\pi^\pm$ + $\pi^\pm$. A cross section is measured in the fiducial region defined by the muon transverse momentum $p_{T}^{\mu} >$ 26 GeV, muon pseudorapidity $|\eta^{\mu}| <$ 2.4, and charm quark transverse momentum $p_{T}^{c} >$ 5 GeV. The inclusive cross section for this kinematic range is $\sigma$(W+c) = 1026 $\pm$ 31 (stat) $\substack{+76\\-72}$ (syst) pb. The cross section is also measured differentially as a function of the pseudorapidity of the muon from the W boson decay. These measurements are compared with theoretical predictions and are used to probe the strange quark content of the proton.
The differential measurement of W + charm as a function of the absolute peudorapidity of the muon originating from the W boson.
The differential measurement of W+ + cbar as a function of the absolute peudorapidity of the muon originating from the W boson.
The differential measurement of W- + c as a function of the absolute peudorapidity of the muon originating from the W boson.
Measurements of differential top quark pair $\mathrm{t\overline{t}}$ cross sections using events produced in proton-proton collisions at a centre-of-mass energy of 13 TeV containing two oppositely charged leptons are presented. The data were recorded by the CMS experiment at the CERN LHC in 2016 and correspond to an integrated luminosity of 35.9 fb$^{-1}$. The differential cross sections are presented as functions of kinematic observables of the top quarks and their decay products, the $\mathrm{t\overline{t}}$ system, and the total number of jets in the event. The differential cross sections are defined both with particle-level objects in a fiducial phase space close to that of the detector acceptance and with parton-level top quarks in the full phase space. All results are compared with standard model predictions from Monte Carlo simulations with next-to-leading-order (NLO) accuracy in quantum chromodynamics (QCD) at matrix-element level interfaced to parton-shower simulations. Where possible, parton-level results are compared to calculations with beyond-NLO precision in QCD. Significant disagreement is observed between data and all predictions for several observables. The measurements are used to constrain the top quark chromomagnetic dipole moment in an effective field theory framework at NLO in QCD and to extract $\mathrm{t\overline{t}}$ and leptonic charge asymmetries.
Measured absolute differential cross section at parton level as a function of $p_{T}^{t}$.
Covariance matrix of the absolute differential cross section at parton level as a function of $p_{T}^{t}$.
Measured normalised differential cross section at parton level as a function of $p_{T}^{t}$.
Measurements of prompt $\psi$(2S) meson production cross sections in proton-lead (pPb) and proton-proton (pp) collisions at a nucleon-nucleon center-of-mass energy of $\sqrt{s_{_\mathrm{NN}}}=$ 5.02 TeV are reported. The results are based on pPb and pp data collected by the CMS experiment at the LHC, corresponding to integrated luminosities of 34.6 nb$^{-1}$ and 28.0 pb$^{-1}$, respectively. The nuclear modification factor $R_\mathrm{pPb}$ is measured for prompt $\psi$(2S) in the transverse momentum range 4 $<$ p$_\mathrm{T}$ $<$ 30 GeV$/c$ and the center-of-mass rapidity range $-$2.4 $< y_\mathrm{cm} <$ 1.93. The results on $\psi$(2S) $R_\mathrm{pPb}$ are compared to the corresponding modification factor for prompt J$/\psi$ mesons and are found to be more suppressed than the J$/\psi$ states over the entire kinematic range studied.
Differential cross section (multiplied by the dimuon branching fraction) of prompt $\psi$(2S) mesons in pPb collisions at $\sqrt(s_{\textrm{NN}})=5.02 $ TeV, as a function of $p_{\textrm{T}}$, for four backward $y_{\mathrm{CM}}$ regions. The fully correlated luminosity uncertainty of 3.5% is not included in the point-by-point uncertainty. NOTE- The cross section unit is nb (nano barn); the y-axes of the figures in the publication show pb (pico barn) by mistake.
Differential cross section (multiplied by the dimuon branching fraction) of prompt $\psi$(2S) mesons in pPb collisions at $\sqrt(s_{\textrm{NN}})=5.02 $ TeV, as a function of $p_{\textrm{T}}$, for three forward $y_{\mathrm{CM}}$ regions. The fully correlated luminosity uncertainty of 3.5% is not included in the point-by-point uncertainty. NOTE- The cross section unit is nb (nano barn); the y-axes of the figures in the publication show pb (pico barn) by mistake.
Differential cross section (multiplied by the dimuon branching fraction) of prompt $\psi$(2S) mesons in pp collisions at $\sqrt(s)=5.02 $ TeV, as a function of $p_{\textrm{T}}$, for four $y_{\mathrm{CM}}$ regions. The fully correlated luminosity uncertainty of 2.3% is not included in the point-by-point uncertainty. NOTE- The cross section unit is nb (nano barn); the y-axes of the figures in the publication show pb (pico barn) by mistake.
The dynamics of isolated-photon production in association with a jet in proton-proton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fb$^{-1}$. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti-$k_t$ algorithm with radius parameter $R=0.4$ and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photon-jet invariant mass and the scattering angle in the photon-jet centre-of-mass system. Tree-level plus parton-shower predictions from SHERPA and PYTHIA as well as next-to-leading-order QCD predictions from JETPHOX and SHERPA are compared to the measurements.
Measured cross sections for isolated-photon plus jet production as a function of $E_{\rm T}^{\gamma}$.
Measured cross sections for isolated-photon plus jet production as a function of $p_{\rm T}^{\rm jet-lead}$.
Measured cross sections for isolated-photon plus jet production as a function of $\Delta\phi^{\rm \gamma-jet\ lead}$.
A measurement of the production of three isolated photons in proton-proton collisions at a centre-of-mass energy $\sqrt{s}$ = 8 TeV is reported. The results are based on an integrated luminosity of 20.2 fb$^{-1}$ collected with the ATLAS detector at the LHC. The differential cross sections are measured as functions of the transverse energy of each photon, the difference in azimuthal angle and in pseudorapidity between pairs of photons, the invariant mass of pairs of photons, and the invariant mass of the triphoton system. A measurement of the inclusive fiducial cross section is also reported. Next-to-leading-order perturbative QCD predictions are compared to the cross-section measurements. The predictions underestimate the measurement of the inclusive fiducial cross section and the differential measurements at low photon transverse energies and invariant masses. They provide adequate descriptions of the measurements at high values of the photon transverse energies, invariant mass of pairs of photons, and invariant mass of the triphoton system.
The three isolated photons cross section with systematic and statistical uncertainties as a function of ET(Photon1).
The three isolated photons cross section with systematic and statistical uncertainties as a function of ET(Photon2).
The three isolated photons cross section with systematic and statistical uncertainties as a function of ET(Photon3).
The differential cross-section for the production of a $W$ boson in association with a top quark is measured for several particle-level observables. The measurements are performed using 36.1 fb$^{-1}$ of $pp$ collision data collected with the ATLAS detector at the LHC in 2015 and 2016. Differential cross-sections are measured in a fiducial phase space defined by the presence of two charged leptons and exactly one jet matched to a $b$-hadron, and are normalised with the fiducial cross-section. Results are found to be in good agreement with predictions from several Monte Carlo event generators.
Fiducial region definition.
Absolute cross-sections differential in E(b). Uncertainties are signed to show correlations.
Absolute cross-sections differential in m(l1b). Uncertainties are signed to show correlations.
This paper presents a measurement of the $W$ boson production cross section and the $W^{+}/W^{-}$ cross-section ratio, both in association with jets, in proton--proton collisions at $\sqrt{s}=8$ TeV with the ATLAS experiment at the Large Hadron Collider. The measurement is performed in final states containing one electron and missing transverse momentum using data corresponding to an integrated luminosity of 20.2 fb$^{-1}$. Differential cross sections for events with one or two jets are presented for a range of observables, including jet transverse momenta and rapidities, the scalar sum of transverse momenta of the visible particles and the missing transverse momentum in the event, and the transverse momentum of the $W$ boson. For a subset of the observables, the differential cross sections of positively and negatively charged $W$ bosons are measured separately. In the cross-section ratio of $W^{+}/W^{-}$ the dominant systematic uncertainties cancel out, improving the measurement precision by up to a factor of nine. The observables and ratios selected for this paper provide valuable input for the up quark, down quark, and gluon parton distribution functions of the proton.
Cross section for the production of W bosons for different inclusive jet multiplicities.
Statistical correlation between bins in data for the cross section for the production of W bosons for different inclusive jet multiplicities.
Differential cross sections for the production of W<sup>+</sup> bosons, W<sup>-</sup> bosons and the W<sup>+</sup>/W<sup>-</sup> cross section ratio as a function of the inclusive jet multiplicity.
Differential production cross sections of J/$\psi$ and $\psi$(2S) charmonium and $\Upsilon$(nS) (n = 1, 2, 3) bottomonium states are measured in proton-proton collisions at $\sqrt{s} =$ 13 TeV, with data collected by the CMS detector at the LHC, corresponding to an integrated luminosity of 2.3 fb$^{-1}$ for the J/$\psi$ and 2.7 fb$^{-1}$ for the other mesons. The five quarkonium states are reconstructed in the dimuon decay channel, for dimuon rapidity $|y| <$ 1.2. The double-differential cross sections for each state are measured as a function of $y$ and transverse momentum, and compared to theoretical expectations. In addition, ratios are presented of cross sections for prompt $\psi$(2S) to J/$\psi$, $\Upsilon$(2S) to $\Upsilon$(1S), and $\Upsilon$(3S) to $\Upsilon$(1S) production.
Double-differential cross section times the dimuon branching fraction of the J/psi meson for different ranges of pT in bins of |y| and for the full |y| < 1.2 range, for the unpolarized decay hypothesis. The global uncertainty in the integrated luminosity of 2.3% is not included in the systematic uncertainties.
Double-differential cross section times the dimuon branching fraction of the psi(2S) meson for different ranges of pT in bins of |y| and for the full |y| < 1.2 range, for the unpolarized decay hypothesis. The global uncertainty in the integrated luminosity of 2.3% is not included in the systematic uncertainties.
Double-differential cross section times the dimuon branching fraction of the Y(1S) meson for different ranges of pT in bins of |y| and for the full |y| < 1.2 range, for the unpolarized decay hypothesis. The global uncertainty in the integrated luminosity of 2.3% is not included in the systematic uncertainties.
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