Pseudorapidity (eta) distributions of charged particles produced in proton-proton collisions at a centre-of-mass energy of 8 TeV are measured in the ranges abs(eta) < 2.2 and 5.3 < abs(eta) < 6.4 covered by the CMS and TOTEM detectors, respectively. The data correspond to an integrated luminosity of 45 inverse microbarns. Measurements are presented for three event categories. The most inclusive category is sensitive to 91-96% of the total inelastic proton-proton cross section. The other two categories are disjoint subsets of the inclusive sample that are either enhanced or depleted in single diffractive dissociation events. The data are compared to models used to describe high-energy hadronic interactions. None of the models considered provide a consistent description of the measured distributions.
Charged particle multiplicity (Inclusive) -- syst -- BB: bin-by-bin uncertainty.
Charged particle multiplicity (Non Single Diffractive dissociation (NSD) enhanced) -- syst -- BB: bin-by-bin uncertainty.
Charged particle multiplicity (Single Diffractive dissociation (SD) enhanced) -- syst -- BB: bin-by-bin uncertainty.
The differential cross sections for inclusive production of B+ hadrons are measured as a function of the B+ transverse momentum pT[B] and rapidity y[B] in pp collisions at a centre-of-mass energy of 13 TeV, using data collected by the CMS experiment that correspond to an integrated luminosity of 49.4 inverse picobarns. The measurement uses the exclusive decay channel B+ to J/psi K+, with J/psi mesons that decay to a pair of muons. The results show a reasonable agreement with theoretical calculations within the uncertainties.
B+ differential production cross sections DSIG/DPT for |yB|< 1.45 or |yB|< 2.1, at 13 TeV. The calculations from FONLL and PYTHIA are provided. The ratio of the data at 13 TeV to the FONLL predictions and the ratios of the PYTHIA to the FONLL calculations are also given.
B+ differential production cross sections DSIG/DETARAP for 10 < ptB < 100 GeV or 17 < ptB < 100 GeV, at 13 TeV. The calculations from FONLL and PYTHIA are provided. The ratio of the data at 13 TeV to the FONLL predictions and the ratios of the PYTHIA to the FONLL calculations are also given.
Ratios of B+ differential production cross sections at 13 TeV and at 7 TeV as a function of ptB for |yB|< 1.45 or |yB|< 2.1. The calculations from FONLL and PYTHIA are provided as well.
Inclusive jet spectra from pp and PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV, collected with the CMS detector at the LHC, are presented. Jets are reconstructed with three different distance parameters (R = 0.2, 0.3, and 0.4) for transverse momentum (pT) greater than 70 GeV and pseudorapidity abs(eta) < 2. Next-to-leading-order quantum chromodynamic calculations with non-perturbative corrections are found to over-predict jet production cross sections in pp for small distance parameters. The jet nuclear modification factors for PbPb compared to pp collisions, show a steady decrease from peripheral to central events, along with a weak dependence on the jet pT. They are found to be independent of the distance parameter in the measured kinematic range.
Raw subtracted $p_T$ for jets reconstructed in PbPb collisions (in different centrality bins) with the anti-k$_T$ algorythm with distance parameter $R=0.3$, in the range $70< p_{T} < 80$GeV/c and $|\eta|<2$. Quantity found by taking the difference of the sum of PF candidates within the jet cone and raw jet $p_T$.
Raw subtracted $p_T$ for jets reconstructed in PbPb collisions (in different centrality bins) with the anti-k$_T$ algorythm with a distance parameter $R=0.3$, in the range $110< p_{T} < 130$GeV/c and $|\eta|<2$. Quantity found by taking the difference of the sum of PF candidates within the jet cone and raw jet $p_T$.
Average raw subtracted $p_T$ for PF jets reconstructed in PbPb collisions (in different centrality bins) with the anti-k$_T$ algorythm with a distance parameter $R=0.3$, in $|\eta|<0.2$.
Charge-dependent azimuthal particle correlations with respect to the second-order event plane in pPb and PbPb collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV have been studied with the CMS experiment at the LHC. The measurement is performed with a three-particle correlation technique, using two particles with the same or opposite charge within the pseudorapidity range abs(eta) < 2.4, and a third particle measured in the hadron forward calorimeters (4.4 < abs(eta) < 5). The observed differences between the same and opposite sign correlations, as functions of multiplicity and eta gap between the two charged particles, are of similar magnitude in pPb and PbPb collisions at the same multiplicities. These results pose a challenge for the interpretation of charge-dependent azimuthal correlations in heavy ion collisions in terms of the chiral magnetic effect.
Three-particle correlation with respect to the 2nd order event plane from Pb-going side in pPb collisions at multiplicity [185,220), with individual track pT between 0.3 to 3.0 GeV/c. Data points are plotted at the bin center.
Three-particle correlation with respect to the 2nd order event plane from p-going side in pPb collisions at multiplicity [185,220), with individual track pT between 0.3 to 3.0 GeV/c. Data points are plotted at the bin center.
Three-particle correlation with respect to the 2nd order event plane in PbPb collisions at multiplicity [185,220), with individual track pT between 0.3 to 3.0 GeV/c. Data points are plotted at the bin center.
The nuclear modification factor RAA and the azimuthal anisotropy coefficient v[2] of prompt and nonprompt (i.e. those from decays of b hadrons) J/psi mesons, measured from PbPb and pp collisions at sqrt(s[NN]) = 2.76 TeV at the LHC, are reported. The results are presented in several event centrality intervals and several kinematic regions, for transverse momenta pt > 6.5 GeV/c and rapidity abs(y) < 2.4, extending down to pt = 3 GeV/c in the 1.6 < abs(y) < 2.4 range. The v[2] of prompt J/psi is found to be nonzero, but with no strong dependence on centrality, rapidity, or pt over the full kinematic range studied. The measured v[2] of nonprompt J/psi is consistent with zero. The RAA of prompt J/psi exhibits a suppression that increases from peripheral to central collisions but does not vary as a function of either y or pt in the fiducial range. The nonprompt J/psi RAA shows a suppression which becomes stronger as rapidity or pt increase. The v[2] and nuclear suppression of open and hidden charm, and of open charm and beauty, are compared.
Prompt J/$\psi$ $v_{2}$ as a function of centrality. The average ${N}_{\rm part}$ values correspond to events flatly distributed across centrality.
Prompt J/$\psi$ $v_{2}$ as a function of rapidity.
Prompt J/$\psi$ $v_{2}$ as a function of $p_{T}$.
Differential and double-differential cross sections for the production of top quark pairs in proton-proton collisions at 13 TeV are measured as a function of jet multiplicity and of kinematic variables of the top quarks and the top quark-antiquark system. This analysis is based on data collected by the CMS experiment at the LHC corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurements are performed in the lepton+jets decay channels with a single muon or electron in the final state. The differential cross sections are presented at particle level, within a phase space close to the experimental acceptance, and at parton level in the full phase space. The results are compared to several standard model predictions.
Absolute cross section at particle level.
Covariance matrix of absolute cross section at particle level.
Absolute cross section at particle level.
Searches for invisible decays of the Higgs boson are presented. The data collected with the CMS detector at the LHC correspond to integrated luminosities of 5.1, 19.7, and 2.3 inverse femtobarns at centre-of-mass energies of 7, 8, and 13 TeV, respectively. The search channels target Higgs boson production via gluon fusion, vector boson fusion, and in association with a vector boson. Upper limits are placed on the branching fraction of the Higgs boson decay to invisible particles, as a function of the assumed production cross sections. The combination of all channels, assuming standard model production, yields an observed (expected) upper limit on the invisible branching fraction of 0.24 (0.23) at the 95% confidence level. The results are also interpreted in the context of Higgs-portal dark matter models.
Observed and expected 95% CL limits on $\sigma\mathcal{B}(H\rightarrow inv)/\sigma(SM)$ for individual combinations of categories targeting qqH, VH, and ggH production, and the full combination assuming a Higgs boson with a mass of 125 GeV.
Profile likelihood ratio as a function of $\mathcal{B}(H\rightarrow inv)$ assuming SM production cross sections of a Higgs boson with a mass of 125 GeV. The solid curves represent the observations in data and the dashed curves represent the expected result assuming no invisible decays of the Higgs boson. The observed and expected likelihood scans for the partial combinations of the qqH tagged, VH tagged, and ggH tagged analyses, and the full combination.
Profile likelihood ratio as a function of $\mathcal{B}(H\rightarrow inv)$ assuming SM production cross sections of a Higgs boson with a mass of 125 GeV. The solid curves represent the observations in data and the dashed curves represent the expected result assuming no invisible decays of the Higgs boson. The observed and expected likelihood scans for the partial combinations of the 7+8 and 13 TeV analyses, and the full combination.
A search for new phenomena is performed in final states containing one or more jets and an imbalance in transverse momentum in pp collisions at a centre-of-mass energy of 13 TeV. The analysed data sample, recorded with the CMS detector at the CERN LHC, corresponds to an integrated luminosity of 2.3 inverse femtobarns. Several kinematic variables are employed to suppress the dominant background, multijet production, as well as to discriminate between other standard model and new physics processes. The search provides sensitivity to a broad range of new-physics models that yield a stable weakly interacting massive particle. The number of observed candidate events is found to agree with the expected contributions from standard model processes, and the result is interpreted in the mass parameter space of fourteen simplified supersymmetric models that assume the pair production of gluinos or squarks and a range of decay modes. For models that assume gluino pair production, masses up to 1575 and 975 GeV are excluded for gluinos and neutralinos, respectively. For models involving the pair production of top squarks and compressed mass spectra, top squark masses up to 400 GeV are excluded.
Summary of the lower bounds of the first and final bins in $H_{\mathrm{T}}$ in [GeV] (the latter in parentheses) as a function of $n_{\text{jet}}$ and $n_{\text{b}}$.
Systematic uncertainties (in percent) in the transfer ($\mathcal{T}$) factors used in the method to estimate the SM backgrounds with genuine $\vec{p}_t^{miss}$ in the signal region. The quoted ranges provide representative values of the observed variations as a function of $n_{\mathrm{jet}}$ and $H_{\mathrm{T}}$.
A summary of the simplified SUSY models used to interpret the results of this search. All on-shell SUSY particles in the decay are stated.
The production yields of Upsilon(1S), Upsilon(2S), and Upsilon(3S) quarkonium states are measured through their decays into muon pairs in the CMS detector, in PbPb and pp collisions at the centre-of-mass energy per nucleon pair of 2.76 TeV. The data correspond to integrated luminosities of 166 inverse microbarns and 5.4 inverse picobarns for PbPb and pp collisions, respectively. Differential production cross sections are reported as functions of Upsilon rapidity y up to 2.4, and transverse momentum pT up to 20 GeV/c. A strong centrality-dependent suppression is observed in PbPb relative to pp collisions, by factors of up to approximately 2 and 8, for the Upsilon(1S) and Upsilon(2S) states, respectively. No significant dependence of this suppression is observed as a function of y or pT. The Upsilon(3S) state is not observed in PbPb collisions, which corresponds to a suppression for the centrality-integrated data by at least a factor of approximately 7 at a 95% confidence level. The observed suppression is in agreement with theoretical scenarios modeling the sequential melting of quarkonium states in a quark gluon plasma.
Differential cross section for Y(1S) states as a function of their transverse momentum and per unit of rapidity in pp collisions. Statistical (systematic) uncertainties are displayed as error bars (boxes). Global relative uncertainties of 3.7% are not displayed.
Differential cross section for Y(2S) states as a function of their transverse momentum and per unit of rapidity in pp collisions. Statistical (systematic) uncertainties are displayed as error bars (boxes). Global relative uncertainties of 3.7% are not displayed.
Differential cross section for Y(3S) states as a function of their transverse momentum and per unit of rapidity in pp collisions. Statistical (systematic) uncertainties are displayed as error bars (boxes). Global relative uncertainties of 3.7% are not displayed.
The relative modification of the prompt psi(2S) and J/psi yields from pp to PbPb collisions, at the center of mass energy of 5.02 TeV per nucleon pair, is presented. The analysis is based on pp and PbPb data samples collected by the CMS experiment at the LHC in 2015, corresponding to integrated luminosities of 28.0 inverse picobarns and 464 inverse microbarns, respectively. The double ratio of measured yields of prompt charmonia reconstructed through their decays into muon pairs, (N[psi(2S)]/N[J/psi])[PbPb] / (N[psi(2S)]/N[J/psi])[pp], is determined as a function of PbPb collision centrality and charmonium transverse momentum pt, in two kinematic intervals: abs(y) < 1.6 covering 6.5 < pt < 30 GeV/c and 1.6 < abs(y) < 2.4 covering 3 < pt < 30 GeV/c. The centrality-integrated double ratios are 0.36 +/- 0.08 (stat) +/-0.05 (syst) in the first interval and 0.24 +/- 0.22 (stat) +/- 0.09 (syst) in the second. The double ratio is lower than unity in all the measured bins, suggesting that the psi(2S) yield is more suppressed than the J/psi yield in the explored phase space.
Double ratio of measured yields, $(N_{\psi\mathrm{(2S)}} / N_{J/\psi})_{\mathrm{PbPb}} / (N_{\psi\mathrm{(2S)}} / N_{J/\psi})_{pp}$, as a function of pT, for the midrapidity analysis bin.
95% CL intervals on the double ratio of measured yields, $(N_{\psi\mathrm{(2S)}} / N_{J/\psi})_{\mathrm{PbPb}} / (N_{\psi\mathrm{(2S)}} / N_{J/\psi})_{pp}$, as a function of pT, for the midrapidity analysis bin.
Double ratio of measured yields, $(N_{\psi\mathrm{(2S)}} / N_{J/\psi})_{\mathrm{PbPb}} / (N_{\psi\mathrm{(2S)}} / N_{J/\psi})_{pp}$, as a function of pT, for the forward rapidity analysis bin.
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