Abstract A search for $$\text {W}\text {W}$$ WW 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 of $$13\,\text {TeV} $$ 13TeV . The analyzed data set corresponds to an integrated luminosity of $$77.4{\,\text {fb}^{-1}} $$ 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 $$\text {W}\text {W}$$ WW production via double-parton scattering, with a significance of 3.9 standard deviations. The measured inclusive cross section is $$1.41\pm 0.28\,\text {(stat)} \pm 0.28\,\text {(syst)} \,\text {pb} $$ 1.41±0.28(stat)±0.28(syst)pb .
Abstract A measurement is presented of electroweak (EW) production of a $$\mathrm{W} $$ W boson in association with two jets in proton–proton collisions at $$\sqrt{s}=13\,\text {Te}\text {V} $$ ...s=13Te . The data sample was recorded by the CMS Collaboration at the LHC and corresponds to an integrated luminosity of 35.9$$\,\text {fb}^{-1}$$ fb-1 . The measurement is performed for the $$\ell \nu $$ ℓν jj final state (with $$\ell \nu $$ ℓν indicating a lepton–neutrino pair, and j representing the quarks produced in the hard interaction) in a kinematic region defined by invariant mass $$m_\mathrm {jj} >120\,\text {Ge}\text {V} $$ mjj>120Ge and transverse momenta $$p_\mathrm {T j} > 25\,\text {Ge}\text {V} $$ pTj>25Ge . The cross section of the process is measured in the electron and muon channels yielding $$\sigma _\mathrm {EW}(\mathrm{W} \mathrm {jj})= 6.23 \pm 0.12 \,\text {(stat)} \pm 0.61 \,\text {(syst)} \,\text {pb} $$ σEW(Wjj)=6.23±0.12(stat)±0.61(syst)pb per channel, in agreement with leading-order standard model predictions. The additional hadronic activity of events in a signal-enriched region is studied, and the measurements are compared with predictions. The final state is also used to perform a search for anomalous trilinear gauge couplings. Limits on anomalous trilinear gauge couplings associated with dimension-six operators are given in the framework of an effective field theory. The corresponding 95% confidence level intervals are $$-2.3< c_{{\mathrm{W} \mathrm{W} \mathrm{W}}}/\varLambda ^2 < 2.5\,\text {Te}\text {V} ^{-2}$$ -2.3<cWWW/Λ2<2.5Te-2 , $$-8.8< c_{\mathrm{W}}/\varLambda ^2 < 16\,\text {Te}\text {V} ^{-2}$$ -8.8<cW/Λ2<16Te-2 , and $$-45< c_{\mathrm{B}}/\varLambda ^2 < 46\,\text {Te}\text {V} ^{-2}$$ -45<cB/Λ2<46Te-2 . These results are combined with the CMS EW $$\mathrm{Zjj} $$ Zjj analysis, yielding the constraint on the $$c_{{\mathrm{W} \mathrm{W} \mathrm{W}}}$$ cWWW coupling: $$-1.8< c_{{\mathrm{W} \mathrm{W} \mathrm{W}}}/\varLambda ^2 < 2.0\,\text {Te}\text {V} ^{-2}$$ -1.8<cWWW/Λ2<2.0Te-2 .
Abstract A search for new physics in top quark production is performed in proton-proton collisions at $$13\,\text {TeV} $$ 13TeV . The data set corresponds to an integrated luminosity of ...$$35.9{\,\text {fb}^{-1}} $$ 35.9fb-1 collected in 2016 with the CMS detector. Events with two opposite-sign isolated leptons (electrons or muons), and $$\mathrm{b}$$ b quark jets in the final state are selected. The search is sensitive to new physics in top quark pair production and in single top quark production in association with a $$\mathrm{W}$$ W boson. No significant deviation from the standard model expectation is observed. Results are interpreted in the framework of effective field theory and constraints on the relevant effective couplings are set, one at a time, using a dedicated multivariate analysis. This analysis differs from previous searches for new physics in the top quark sector by explicitly separating $$\mathrm{t}\mathrm{W}$$ tW from $$\mathrm{t}{\bar{\mathrm{t}}}$$ tt¯ events and exploiting the specific sensitivity of the $$\mathrm{t}\mathrm{W}$$ tW process to new physics.
Abstract The average total energy as well as its hadronic and electromagnetic components are measured with the CMS detector at pseudorapidities $$-6.6<\eta <-5.2$$ -6.6<η<-5.2 in proton-proton ...collisions at a centre-of-mass energy $$\sqrt{s}=13\,\text {TeV} $$ s=13TeV . The results are presented as a function of the charged particle multiplicity in the region $$|\eta |<2$$ |η|<2 . This measurement is sensitive to correlations induced by the underlying event structure over a very wide pseudorapidity region. The predictions of Monte Carlo event generators commonly used in collider experiments and ultra-high energy cosmic ray physics are compared to the data. All generators considered overestimate the fraction of energy going into hadrons.
Abstract A measurement for inclusive 2- and 3-jet events of the azimuthal correlation between the two jets with the largest transverse momenta, $$\varDelta \phi _{12}$$ Δϕ12 , is presented. The ...measurement considers events where the two leading jets are nearly collinear (“back-to-back”) in the transverse plane and is performed for several ranges of the leading jet transverse momentum. Proton-proton collision data collected with the CMS experiment at a center-of-mass energy of $$13\,\text {Te}\text {V} $$ 13Te and corresponding to an integrated luminosity of $$35.9{\,\text {fb}^{-1}} $$ 35.9fb-1 are used. Predictions based on calculations using matrix elements at leading-order and next-to-leading-order accuracy in perturbative quantum chromodynamics supplemented with leading-log parton showers and hadronization are generally in agreement with the measurements. Discrepancies between the measurement and theoretical predictions are as large as 15%, mainly in the region $$177^\circ< \varDelta \phi _{12} < 180^\circ $$ 177∘<Δϕ12<180∘ . The 2- and 3-jet measurements are not simultaneously described by any of models.
A search for a heavy resonance decaying into a top quark and antiquark $ \left(\mathrm{t}\overline{\mathrm{t}}\right) $ pair is performed using proton-proton collisions at $ \sqrt{s}=13 $ TeV. The ...search uses the data set collected with the CMS detector in 2016, which corresponds to an integrated luminosity of 35.9 fb$^{−1}$. The analysis considers three exclusive final states and uses reconstruction techniques that are optimized for top quarks with high Lorentz boosts, which requires the use of nonisolated leptons and jet substructure techniques. No significant excess of events relative to the expected yield from standard model processes is observed. Upper limits on the production cross section of heavy resonances decaying to a $ \mathrm{t}\overline{\mathrm{t}} $ pair are calculated. Limits are derived for a leptophobic topcolor Z$^{′}$ resonance with widths of 1, 10, and 30%, relative to the mass of the resonance, and exclude masses up to 3.80, 5.25, and 6.65 TeV, respectively. Kaluza-Klein excitations of the gluon in the Randall-Sundrum model are excluded up to 4.55 TeV. To date, these are the most stringent limits on $ \mathrm{t}\overline{\mathrm{t}} $ resonances.
Abstract Exclusive $${{{\uprho _{}^{}} _{}^{}}{{\left( {770}\right) }{}_{}^{}}} ^{0}$$ ρ7700 photoproduction is measured for the first time in ultraperipheral pPb collisions at $$\sqrt{\smash ...b{s_{_{\mathrm {NN}}} = 5.02\,\text {Te}\text {V} $$ sNN=5.02Te with the CMS detector. The cross section $$\sigma ({\upgamma _{}^{}} \mathrm{p}\rightarrow {{{\uprho _{}^{}} _{}^{}}{{\left( {770}\right) }{}_{}^{}}} ^{0}\mathrm{p})$$ σ(γp→ρ7700p) is $$11.0 \pm 1.4\,\text {(stat)} \pm 1.0\,\text {(syst)} $$ 11.0±1.4(stat)±1.0(syst) $$\mu $$ μ b at $$\langle W_{{\upgamma _{}^{}} \mathrm{p}}\rangle = 92.6\,\text {Ge}\text {V} $$ ⟨Wγp⟩=92.6Ge for photon–proton centre-of-mass energies $$W_{{\upgamma _{}^{}} \mathrm{p}}$$ Wγp between 29 and $$213\,\text {Ge}\text {V} $$ 213Ge . The differential cross section $$\mathrm {d}\sigma /\mathrm {d}|t |$$ dσ/d|t| is measured in the interval $$0.025< |t | < 1\,\text {Ge}\text {V} ^{2}$$ 0.025<|t|<1Ge2 as a function of $$W_{{\upgamma _{}^{}} \mathrm{p}}$$ Wγp , where t is the squared four-momentum transfer at the proton vertex. The results are compared with previous measurements and theoretical predictions. The measured cross section $$\sigma ({\upgamma _{}^{}} \mathrm{p}\rightarrow {{{\uprho _{}^{}} _{}^{}}{{\left( {770}\right) }{}_{}^{}}} ^{0}\mathrm{p})$$ σ(γp→ρ7700p) has a power-law dependence on the photon–proton centre-of-mass, consistent with electron–proton collision measurements performed at HERA. The $$W_{{\upgamma _{}^{}} \mathrm{p}}$$ Wγp dependence of the exponential slope of the differential cross section $$\mathrm {d}\sigma /\mathrm {d}|t |$$ dσ/d|t| is also measured.
Abstract A search is presented for a heavy pseudoscalar boson $$\text {A}$$ A decaying to a Z boson and a Higgs boson with mass of 125$$\,\text {GeV}$$ GeV . In the final state considered, the Higgs ...boson decays to a bottom quark and antiquark, and the Z boson decays either into a pair of electrons, muons, or neutrinos. The analysis is performed using a data sample corresponding to an integrated luminosity of 35.9$$\,\text {fb}^{-1}$$ fb-1 collected in 2016 by the CMS experiment at the LHC from proton–proton collisions at a center-of-mass energy of 13$$\,\text {Te}\text {V}$$ Te . The data are found to be consistent with the background expectations. Exclusion limits are set in the context of two-Higgs-doublet models in the $$\text {A}$$ A boson mass range between 225 and 1000$$\,\text {GeV}$$ GeV .
Abstract Combined measurements of the production and decay rates of the Higgs boson, as well as its couplings to vector bosons and fermions, are presented. The analysis uses the LHC proton–proton ...collision data set recorded with the CMS detector in 2016 at $$\sqrt{s}=13\,\text {Te}\text {V} $$ s=13Te , corresponding to an integrated luminosity of 35.9$${\,\text {fb}^{-1}} $$ fb-1 . The combination is based on analyses targeting the five main Higgs boson production mechanisms (gluon fusion, vector boson fusion, and associated production with a $$\mathrm {W}$$ W or $$\mathrm {Z}$$ Z boson, or a top quark-antiquark pair) and the following decay modes: $$\mathrm {H} \rightarrow \gamma \gamma $$ H→γγ , $$\mathrm {Z}\mathrm {Z}$$ ZZ , $$\mathrm {W}\mathrm {W}$$ WW , $$\mathrm {\tau }\mathrm {\tau }$$ ττ , $$\mathrm {b} \mathrm {b} $$ bb , and $$\mathrm {\mu }\mathrm {\mu }$$ μμ . Searches for invisible Higgs boson decays are also considered. The best-fit ratio of the signal yield to the standard model expectation is measured to be $$\mu =1.17\pm 0.10$$ μ=1.17±0.10 , assuming a Higgs boson mass of $$125.09\,\text {Ge}\text {V} $$ 125.09Ge . Additional results are given for various assumptions on the scaling behavior of the production and decay modes, including generic parametrizations based on ratios of cross sections and branching fractions or couplings. The results are compatible with the standard model predictions in all parametrizations considered. In addition, constraints are placed on various two Higgs doublet models.
Abstract A measurement of the energy density in proton–proton collisions at a centre-of-mass energy of $$\sqrt{s} =13$$ s=13 $$\,\text {TeV}$$ TeV is presented. The data have been recorded with the ...CMS experiment at the LHC during low luminosity operations in 2015. The energy density is studied as a function of pseudorapidity in the ranges $$-\,6.6<\eta <-\,5.2$$ -6.6<η<-5.2 and $$3.15<|\eta |<5.20$$ 3.15<|η|<5.20 . The results are compared with the predictions of several models. All the models considered suggest a different shape of the pseudorapidity dependence compared to that observed in the data. A comparison with LHC proton–proton collision data at $$\sqrt{s} =0.9$$ s=0.9 and $$7\,\text {TeV} $$ 7TeV confirms the compatibility of the data with the hypothesis of limiting fragmentation.
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