Top-quark mass measurement using events with missing transverse energy and jets at CDF
Physical Review Letters 107:23 (2011)
Abstract:
We present a measurement of the top-quark mass using a sample of tt̄ events in 5.7fb-1 of integrated luminosity from pp̄ collisions at the Fermilab Tevatron with √s=1.96TeV and collected by the CDF II Detector. We select events having large missing transverse energy, and four, five, or six jets with at least one jet tagged as coming from a b quark, and reject events with identified charged leptons. This analysis considers events from the semileptonic tt̄ decay channel, including events that contain tau leptons. The measurement is based on a multidimensional template method. We fit the data to signal templates of varying top-quark masses and background templates, and measure a top-quark mass of Mtop=172.32±2. 4(stat)±1.0(syst)GeV/c2. © 2011 American Physical Society.Measurement of the transverse momentum distribution of Z/γ* bosons in proton-proton collisions at s=7 TeV with the ATLAS detector
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 705:5 (2011) 415-434
Abstract:
A measurement of the Z/γ* transverse momentum (pTZ) distribution in proton-proton collisions at s=7 TeV is presented using Z/γ*→e+e- and Z/γ*→μ+μ- decays collected with the ATLAS detector in data sets with integrated luminosities of 35 pb-1 and 40 pb-1, respectively. The normalized differential cross sections are measured separately for electron and muon decay channels as well as for their combination up to pTZ of 350 GeV for invariant dilepton masses 66 GeVSearch for supersymmetry in pp collisions at √s = 7 TeV in events with a single lepton, jets, and missing transverse momentum
Journal of High Energy Physics 2011:8 (2011)
Abstract:
Results are reported from a search for physics beyond the standard model in proton-proton collisions at a center-of-mass energy of 7TeV, 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 for the production of tt̄ and W+jets events. The results are interpreted in terms of limits on the parameter space for the constrained minimal supersymmetric extension of the standard model.Search for the Standard Model Higgs boson in the decay channel H→ZZ(*)→4ℓ with the ATLAS detector
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 705:5 (2011) 435-451
Abstract:
A search for the Standard Model Higgs boson in the decay channel H→ZZ(*)→ℓ+ℓ-ℓ'+ℓ'-, where ℓ=e, μ, is presented. Proton-proton collision data at s=7TeV recorded with the ATLAS detector and corresponding to an average integrated luminosity of 2.1fb-1 are compared to the Standard Model expectations. Upper limits on the production cross section of a Standard Model Higgs boson with a mass between 110 and 600GeV are derived. The observed (expected) 95% confidence level upper limit on the production cross section for a Higgs boson with a mass of 194 GeV, the region with the best expected sensitivity for this search, is 0.99 (1.01) times the Standard Model prediction. The Standard Model Higgs boson is excluded at 95% confidence level in the mass ranges 191-197, 199-200 and 214-224 GeV. © 2011 CERN.Search for a Standard Model Higgs Boson in the H→ZZ→ℓ+ℓ−νν¯ Decay Channel with the ATLAS Detector
Physical Review Letters 107:22 (2011)