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Events with no charged particles produced between the two leading jets are studied in proton-proton collisions at

Abstract 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 $$\\,\\text {Te}\\text {V}$$Te by the CMS experiment at the LHC. From a data set corresponding to an integrated luminosity of 35.9 $$\\,\\text {fb}^{-1}$$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 ( $$p_{\\mathrm{T}} $$pT ), rapidity, and polarisation angle, the charged lepton$$p_{\\mathrm{T}} $$pT and rapidity, and the$$p_{\\mathrm{T}} $$pT of the$$\\text {W}{}{}$$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$$\\text {W}{}{}$$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$$0.440 \\pm 0.070$$0.440±0.070 , in agreement with the standard model prediction.

Abstract A search in an all-jet final state for new massive resonances decaying to\\text{ W }{}{}W\\text{ W }{}{}W ,\\text{ W }{}{}W\\text{ Z }{}{}Z , or\\text{ Z }{}{}Z\\text{ Z }{}{}Z boson pairs using a novel analysis method is presented. The analysis is performed on data corresponding to an integrated luminosity of 77.3 \\text fb⁻¹fb-1 recorded with the CMS experiment at the LHC at a centre-of-mass energy of 13  \\text Te\\text VTe . The search is focussed on potential narrow-width resonances with masses above 1.2  \\text Te\\text VTe , where the decay products of each\\text{ W }{}{}W or\\text{ Z }{}{}Z boson are expected to be collimated into a single, large-radius jet. The signal is extracted using a three-dimensional maximum likelihood fit of the two jet masses and the dijet invariant mass, yielding an improvement in sensitivity of up to 30% relative to previous search methods. No excess is observed above the estimated standard model background. In a heavy vector triplet model, spin-1\\text Z^(′)Z′ and\\text W^(′)W′ resonances with masses below 3.5 and 3.8   \\text Te\\text VTe , respectively, are excluded at 95% confidence level. In a bulk graviton model, upper limits on cross sections are set between 27 and 0.2 \\text fbfb for resonance masses between 1.2 and 5.2   \\text Te\\text VTe , respectively. The limits presented in this paper are the best to date in the dijet final state.

Abstract A search for\\text W\\text WWW production from double-parton scattering processes using same-charge electron-muon and dimuon events is reported, based on proton-proton collision data collected at a center-of-mass energy of13 \\text TeV 13TeV . The analyzed data set corresponds to an integrated luminosity of77.4 \\text fb⁻¹ 77.4fb-1 , collected using the CMS detector at the LHC in 2016 and 2017. Multivariate classifiers are used to discriminate between the signal and the dominant background processes. A maximum likelihood fit is performed to extract the signal cross section. This leads to the first evidence for\\text W\\text WWW production via double-parton scattering, with a significance of 3.9 standard deviations. The measured inclusive cross section is1.41± 0.28 \\text (stat) ± 0.28 \\text (syst) \\text pb 1.41±0.28(stat)±0.28(syst)pb .

Abstract A search for new physics is carried out in events with at least three electrons or muons in any combination, jets, and missing transverse momentum. Results are based on the sample of proton-proton collision data produced by the LHC at a center-of-mass energy of 13 TeV and collected by the CMS experiment in 2016. The data sample analyzed corresponds to an integrated luminosity of 35.9 fb−1. Events are classified according to the number of b jets, missing transverse momentum, hadronic transverse momentum, and the invariant mass of same-flavor dilepton pairs with opposite charge. No significant excess above the expected standard model background is observed. Exclusion limits at 95% confidence level are computed for four different supersymmetric simplified models with pair production of gluinos or third-generation squarks. In the model with gluino pair production, with subsequent decays into a top quark-antiquark pair and a neutralino, gluinos with masses smaller than 1610 GeV are excluded for a massless lightest supersymmetric particle. In the case of bottom squark pair production, the bottom squark masses are excluded up to 840 GeV for charginos lighter than 200 GeV. For a simplified model of heavy top squark pair production, the t˜2$$ {\\tilde{\\mathrm{t}}}_2 $$mass is excluded up to 720, 780, or 710 GeV for models with an exclusive t˜2→t˜1H$$ {\\tilde{\\mathrm{t}}}_2\\to {\\tilde{\\mathrm{t}}}_1\\mathrm{H} $$decay, an exclusive t˜2→t˜1Z$$ {\\tilde{\\mathrm{t}}}_2\\to {\\tilde{\\mathrm{t}}}_1\\mathrm{Z} $$decay, or an equally probable mix of those two decays. In order to provide a simplified version of the analysis for easier interpretation, a small set of aggregate signal regions also has been defined, providing a compromise between simplicity and analysis sensitivity.

Abstract A first search for same-sign WW production via double-parton scattering is performed based on proton-proton collision data at a center-of-mass energy of 8 TeV using dimuon and electron-muon final states. The search is based on the analysis of data corresponding to an integrated luminosity of 19.7 fb−1. No significant excess of events is observed above the expected single-parton scattering yields. A 95% confidence level upper limit of 0.32 pb is set on the inclusive cross section for same-sign WW production via the double-parton scattering process. This upper limit is used to place a 95% confidence level lower limit of 12.2 mb on the effective double-parton cross section parameter, closely related to the transverse distribution of partons in the proton. This limit on the effective cross section is consistent with previous measurements as well as with Monte Carlo event generator predictions.

Abstract A search for narrow vector resonances decaying into quark-antiquark pairs is presented. The analysis is based on data collected in proton-proton collisions at s=13 √s̅=13 TeV with the CMS detector at the LHC, corresponding to an integrated luminosity of 35.9 fb−1. The hypothetical resonance is produced with sufficiently high transverse momentum that its decay products are merged into a single jet with two-prong substructure. A signal would be identified as a peak over a smoothly falling background in the distribution of the invariant mass of the jet, using novel jet substructure techniques. No evidence for such a resonance is observed within the mass range of 50-300 GeV. Upper limits at 95% confidence level are set on the production cross section, and presented in a mass-coupling parameter space. The limits further constrain simplified models of dark matter production involving a mediator interacting between quarks and dark matter particles through a vector or axial-vector current. In the framework of these models, the results are the most sensitive to date, extending for the first time the search region to masses below 100 GeV.

In the original paper, figure 10 was incorrect. The correct figure is shown below. Additionally, the unparticle entries in table 3, as well as figure 4 and 5 were labelled with incorrect values of ΛU.

Abstract A search for physics beyond the standard model in final states with at least one photon, large transverse momentum imbalance, and large total transverse event activity is presented. Such topologies can be produced in gauge-mediated supersymmetry models in which pair-produced gluinos or squarks decay to photons and gravitinos via short-lived neutralinos. The data sample corresponds to an integrated luminosity of 35.9 fb−1 of proton-proton collisions at s=13 √s̅=13 TeV recorded by the CMS experiment at the LHC in 2016. No significant excess of events above the expected standard model background is observed. The data are interpreted in simplified models of gluino and squark pair production, in which gluinos or squarks decay via neutralinos to photons. Gluino masses of up to 1.50-2.00 TeV and squark masses up to 1.30-1.65 TeV are excluded at 95% confidence level, depending on the neutralino mass and branching fraction.

Abstract A search is presented for decays beyond the standard model of the 125 GeV Higgs bosons to a pair of light bosons, based on models with extended scalar sectors. Light boson masses between 5 and 62.5 GeV are probed in final states containing four τ leptons, two muons and two b quarks, or two muons and two τ leptons. The results are from data in proton-proton collisions corresponding to an integrated luminosity of 19.7 fb−1, accumulated by the CMS experiment at the LHC at a center-of-mass energy of 8 TeV. No evidence for such exotic decays is found in the data. Upper limits are set on the product of the cross section and branching fraction for several signal processes. The results are also compared to predictions of two-Higgs-doublet models, including those with an additional scalar singlet.