1,255 research outputs found
Pseudorapidity and transverse momentum dependence of flow harmonics in pPb and PbPb collisions
Search for supersymmetry in events with a τ lepton pair and missing transverse momentum in proton-proton collisions at √s=13 TeV
A search for the electroweak production of supersymmetric particles in proton-proton collisions at a center-of-mass energy of 13 TeV is presented in final states with a lepton pair. Both hadronic and leptonic decay modes are considered for the leptons. Scenarios involving the direct pair production of sleptons, or their indirect production via the decays of charginos and neutralinos, are investigated. The data correspond to an integrated luminosity of 35.9 fb collected with the CMS detector in 2016. The observed number of events is consistent with the standard model background expectation. The results are interpreted as upper limits on the cross section for slepton pair production in different scenarios. The strongest limits are observed in the scenario of a purely left-handed slepton with a mass of 90 GeV decaying to a nearly massless neutralino, and correspond to 1.26 times the expected production cross section in the simplified model considered. Exclusion limits are also set in the context of simplified models of chargino-neutralino and chargino pair production with decays to leptons, and range up to 710 and 630 GeV, respectively
Search for physics beyond the standard model in high-mass diphoton events from proton-proton collisions at root s=13 TeV
A search for physics beyond the standard model is performed using a sample of high-mass diphoton events produced in proton-proton collisions at 13 TeV. The data sample was collected in 2016 with the CMS detector at the LHC and corresponds to an integrated luminosity of 35.9 fb. The search is performed for both resonant and nonresonant new physics signatures. At 95% confidence level, lower limits on the mass of the first Kaluza-Klein excitation of the graviton in the Randall-Sundrum warped extra-dimensional model are determined to be in the range of 2.3 to 4.6 TeV, for values of the associated coupling parameter between 0.01 and 0.2. Lower limits on the production of scalar resonances and model-independent cross section upper limits are also provided. For the large extra-dimensional model of Arkani-Hamed, Dimopoulos, and Dvali, lower limits are set on the string mass scale ranging from 5.6 to 9.7 TeV, depending on the model parameters. The first exclusion limits are set in the two-dimensional parameter space of a continuum clockwork model
Measurement of jet substructure observables in t(t)over-bar events from proton-proton collisions at root s=13 TeV
Measurement of differential cross sections for Z boson production in association with jets in proton-proton collisions at √s=13TeV
The production of a Z boson, decaying to two charged leptons, in association with jets in proton- proton collisions at a centre- of- mass energy of 13 TeV is measured. Data recorded with the CMS detector at the LHC are used that correspond to an integrated luminosity of 2.19 fb - 1. The cross section is measured as a function of the jet multiplicity and its dependence on the transverse momentum of the Z boson, the jet kinematic variables ( transverse momentum and rapidity), the scalar sum of the jet momenta, which quantifies the hadronic activity, and the balance in transverse momentum between the reconstructed jet recoil and the Z boson. The measurements are compared with predictions from four different calculations. The first two merge matrix elements with different parton multiplicities in the final state and parton showering, one of which includes oneloop corrections. The third is a fixed- order calculation with next- to- next- to- leading order accuracy for the process with a Z boson and one parton in the final state. The fourth combines the fully differential next- to- next- to- leading order calculation of the process with no parton in the final state with next- to- next- to- leading logarithm resummation and parton showering
Suppression and azimuthal anisotropy of prompt and nonprompt J / ψ production in PbPb collisions at √sNN=2.76TeV
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.
Search for the decay of a Higgs boson in the ℓℓγ channel in proton-proton collisions at √s=13 TeV
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