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Articles 1 - 12 of 12
Full-Text Articles in Physical Sciences and Mathematics
Long-Range And Short-Range Dihadron Angular Correlations In Central Pbpb Collisions At Psnn = 2:76 Tev, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert Ralich, Igor Vodopiyanov, The Cms Collaboration
Long-Range And Short-Range Dihadron Angular Correlations In Central Pbpb Collisions At Psnn = 2:76 Tev, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert Ralich, Igor Vodopiyanov, The Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
First measurements of dihadron correlations for charged particles are presented for central PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV over a broad range in relative pseudorapidity (∆η) and the full range of relative azimuthal angle (∆η). The data were collected with the CMS detector, at the LHC. A broadening of the away-side (∆ϕ ≈ π) azimuthal correlation is observed at all ∆η, as compared to the measurements in pp collisions. Furthermore, long-range dihadron correlations in ∆η are observed for particles with similar ϕ values. This phenomenon, also known as the “ridge”, persists up to at least |∆η| …
Search For Light Resonances Decaying Into Pairs Of Muons As A Signal Of New Physics, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert M. Ralich, Igor Vodopiyanov, The Cms Collaboration
Search For Light Resonances Decaying Into Pairs Of Muons As A Signal Of New Physics, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert M. Ralich, Igor Vodopiyanov, The Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
A search for groups of collimated muons is performed using a data sample collected by the CMS experiment at the LHC, at a centre-of-mass energy of 7 TeV, and corresponding to an integrated luminosity of 35 pb−1 . The analysis searches for production of new low-mass states decaying into pairs of muons and is designed to achieve high sensitivity to a broad range of models predicting leptonic jet signatures. With no excess observed over the background expectation, upper limits on the production cross section times branching fraction times acceptance are set, ranging from 0.1 to 0.5 pb at the 95% …
Search For New Physics With Jets And Missing Transverse Momentum In Pp Collisions At √S = 7 Tev, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert M. Ralich, Igor Vodopiyanov, The Cms Collaboration
Search For New Physics With Jets And Missing Transverse Momentum In Pp Collisions At √S = 7 Tev, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert M. Ralich, Igor Vodopiyanov, The Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 pb−1 collected in proton-proton collisions at √s = 7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected …
Measurement Of The Inclusive W And Z Production Cross Sections In Pp Collisions At √S = 7 Tev With The Cms Experiment, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Igor Vodopiyanov, The Cms Collaboration
Measurement Of The Inclusive W And Z Production Cross Sections In Pp Collisions At √S = 7 Tev With The Cms Experiment, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Igor Vodopiyanov, The Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
A measurement of inclusive W and Z production cross sections in pp collisions at √s = 7 TeV is presented. The electron and muon decay channels are analyzed in a data sample collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 36 pb−1. The measured inclusive cross sections are σ(pp → WX) × B(W→ℓν) = 10.31 ± 0.02 (stat.) ± 0.09 (syst.) ± 0.10 (th.) ± 0.41 (lumi.) nb and σ(pp → ZX) × B(Z→ℓ+ℓ−) = 0.974 ± 0.007 (stat.) ± 0.007 (syst.) ± 0.018 (th.) ± 0.039 (lumi.) nb, limited to the dilepton …
Measurement Of The Underlying Event Activity At The Lhc With √S = 7 Tev And Comparison With √S = 0.9 Tev, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert M. Ralich, Igor Vodopiyanov, The Cms Collaboration
Measurement Of The Underlying Event Activity At The Lhc With √S = 7 Tev And Comparison With √S = 0.9 Tev, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert M. Ralich, Igor Vodopiyanov, The Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
A measurement of the underlying activity in events with a jet of transverse momentum in the several GeV region is performed in proton-proton collisions at √s = 0.9 and 7 TeV, using data collected by the CMS experiment at the LHC. The production of charged particles with pseudorapidity |η|<2 and transverse momentum pT >0.5 GeV/c is studied in the azimuthal region transverse to that of the leading set of charged particles forming a track-jet. A significant growth of the average multiplicity and scalar-pT sum of the particles in the transverse region is observed with increasing pT of the leading trackjet, followed by a much …
Measurements Of Inclusive W And Z Cross Sections In Pp Collisions At √S = 7 Tev, V. Khachatryan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert M. Ralich, Igor Vodopiyanov, The Cms Collaboration
Measurements Of Inclusive W And Z Cross Sections In Pp Collisions At √S = 7 Tev, V. Khachatryan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert M. Ralich, Igor Vodopiyanov, The Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
Measurements of inclusive W and Z boson production cross sections in pp collisions at √s = 7 TeV are presented, based on 2.9 pb−1 of data recorded by the CMS detector at the LHC. The measurements, performed in the electron and muon decay channels, are combined to give σ(pp→WX) × B(W→ℓν) = 9.95 ± 0.07 (stat.) ± 0.28 (syst.) ±1.09 (lumi.) nb and σ(pp→ZX) × B(Z→ℓ+ℓ−) = 0.931 ± 0.026 stat.) ± 0.023 (syst.) ± 0.102 (lumi.) nb, where ℓ stands for either e or μ. Theoretical predictions, calculated at the next-to-next-to-leading order in QCD using recent parton distribution functions, …
Measurement Of The Drell-Yan Cross Section In Pp Collisions At √S = 7 Tev, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Marcus Hohlmann, Himali Kalakhety, Igor Vodopiyanov, The Cms Collaboration
Measurement Of The Drell-Yan Cross Section In Pp Collisions At √S = 7 Tev, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Marcus Hohlmann, Himali Kalakhety, Igor Vodopiyanov, The Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
The Drell-Yan differential cross section is measured in pp collisions at √s = 7 TeV, from a data sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 36 pb−1. The cross section measurement, normalized to the measured cross section in the Z region, is reported for both the dimuon and dielectron channels in the dilepton invariant mass range 15–600 GeV. The normalized cross section values are quoted both in the full phase space and within the detector acceptance. The effect of final state radiation is also identified. The results are found to agree with …
Search For Resonances In The Dilepton Mass Distribution In Pp Collisions At √S = 7tev, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert M. Ralich, Igor Vodopiyanov, The Cms Collaboration
Search For Resonances In The Dilepton Mass Distribution In Pp Collisions At √S = 7tev, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert M. Ralich, Igor Vodopiyanov, The Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
A search for narrow resonances at high mass in the dimuon and dielectron channels has been performed by the CMS experiment at the CERN LHC, using pp collision data recorded at √s = 7 TeV. The event samples correspond to integrated luminosities of 40 pb−1 in the dimuon channel and 35 pb−1 in the dielectron channel. Heavy dilepton resonances are predicted in theoretical models with extra gauge bosons (Z′) or as Kaluza-Klein graviton excitations (GKK) in the Randall-Sundrum model. Upper limits on the inclusive cross section of Z′(GKK) → ℓ+ℓ− relative to Z → ℓ+ℓ− are presented. These limits exclude …
Charged Particle Transverse Momentum Spectra In Pp Collisions At √S = 0:9 And 7 Tev, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert M. Ralich, Igor Vodopiyanov, The Cms Collaboration
Charged Particle Transverse Momentum Spectra In Pp Collisions At √S = 0:9 And 7 Tev, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert M. Ralich, Igor Vodopiyanov, The Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
The charged particle transverse momentum (pT) spectra are presented for pp collisions at √s = 0.9 and 7 TeV. The data samples were collected with the CMS detector at the LHC and correspond to integrated luminosities of 231 μb−1 and 2.96 pb−1, respectively. Calorimeter-based high-transverse-energy triggers are employed to enhance the statistical reach of the high-pT measurements. The results are compared with leading and next-to-leading order QCD and with an empirical scaling of measurements at different collision energies using the scaling variable xT ≡ 2pT / √s over the pT range up to 200 GeV / c. Using a combination …
Measurement Of The Lepton Charge Asymmetry In Inclusive W Production In Pp Collisions At √S = 7 Tev, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert M. Ralich, Igor Vodopiyanov, The Cms Collaboration
Measurement Of The Lepton Charge Asymmetry In Inclusive W Production In Pp Collisions At √S = 7 Tev, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert M. Ralich, Igor Vodopiyanov, The Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
A measurement of the lepton charge asymmetry in inclusive pp → WX production at √s = 7 TeV is presented based on data recorded by the CMS detector at the LHC and corresponding to an integrated luminosity of 36 pb−1. This high precision measurement of the lepton charge asymmetry, performed in both the W → eν and W → μν channels, provides new insights into parton distribution functions.
Charged Particle Multiplicities In Pp Interactions At √S = 0.9, 2.36, And 7 Tev, V. Khachatryan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert M. Ralich, Igor Vodopiyanov, The Cms Collaboration
Charged Particle Multiplicities In Pp Interactions At √S = 0.9, 2.36, And 7 Tev, V. Khachatryan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert M. Ralich, Igor Vodopiyanov, The Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
Measurements of primary charged hadron multiplicity distributions are presented for non-single-diffractive events in proton-proton collisions at centre-of-mass energies of √s = 0.9, 2.36, and 7 TeV, in five pseudorapidity ranges from |η| < 0.5 to |η| < 2.4. The data were collected with the minimum-bias trigger of the CMS experiment during the LHC commissioning runs in 2009 and the 7 TeV run in 2010. The multiplicity distribution at √s = 0.9 TeV is in agreement with previous measurements. At higher energies the increase of the mean multiplicity with √s is underestimated by most event generators. The average transverse momentum as a function of the multiplicity is also presented. The measurement of higher-order moments of the multiplicity distribution confirms the violation of Koba-Nielsen-Olesen scaling that has been observed at lower energies.
Search For Supersymmetry In Pp Collisions At √S = 7 Tev In Events With A Single Lepton, Jets, And Missing Transverse, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert M. Ralich, Igor Vodopiyanov, The Cms Collaboration
Search For Supersymmetry In Pp Collisions At √S = 7 Tev In Events With A Single Lepton, Jets, And Missing Transverse, S. Chatrchyan, Marc M. Baarmand, B. Dorney, Samir Guragain, Marcus Hohlmann, Himali Kalakhety, Robert M. Ralich, Igor Vodopiyanov, The Cms Collaboration
Aerospace, Physics, and Space Science Faculty Publications
Results are reported from a search for physics beyond the standard model in proton-proton collisions at a center-of-mass energy of 7 TeV, focusing on the signature with a single, isolated, high-transverse-momentum lepton (electron or muon), energetic jets, and large missing transverse momentum. The data sample comprises an integrated luminosity of 36 pb−1, recorded by the CMS experiment at the LHC. The search is motivated by models of new physics, including supersymmetry. The observed event yields are consistent with standard model backgrounds predicted using control samples obtained from the data. The characteristics of the event sample are consistent with those expected …