Measurement of D *± meson production in jets from pp collisions at √s=7TeV with the ATLAS detector
Physical Review D - Particles, Fields, Gravitation and Cosmology 85:5 (2012)
Abstract:
This paper reports a measurement of D *± meson production in jets from proton-proton collisions at a center-of-mass energy of √s=7TeV at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of 0.30pb -1 for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range |η|<2.5. D *± mesons found in jets are fully reconstructed in the decay chain: D *+→D0π +, D0→K -π +, and its charge conjugate. The production rate is found to be N(D *±)/N(jet)=0.025±0. 001(stat.)±0.004(syst.) for D *± mesons that carry a fraction z of the jet momentum in the range 0.3Searches for supersymmetry with the ATLAS detector using final states with two leptons and missing transverse momentum in s=7TeV proton-proton collisions
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 709:3 (2012) 137-157
Abstract:
Results of three searches are presented for the production of supersymmetric particles decaying into final states with missing transverse momentum and exactly two isolated leptons, e or μ. The analysis uses a data sample collected during the first half of 2011 that corresponds to a total integrated luminosity of 1fb-1 of s=7TeV proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider. Opposite-sign and same-sign dilepton events are separately studied, with no deviations from the Standard Model expectation observed. Additionally, in opposite-sign events, a search is made for an excess of same-flavour over different-flavour lepton pairs. Effective production cross sections in excess of 9.9 fb for opposite-sign events containing supersymmetric particles with missing transverse momentum greater than 250 GeV are excluded at 95% CL. For same-sign events containing supersymmetric particles with missing transverse momentum greater than 100 GeV, effective production cross sections in excess of 14.8 fb are excluded at 95% CL. The latter limit is interpreted in a simplified electroweak gaugino production model excluding chargino masses up to 200 GeV, under the assumption that slepton decay is dominant. © 2012 CERN.Search for the Higgs Boson in the H→WW(*)→l +νl-ν̄ Decay Channel in pp Collisions at √s=7TeV with the ATLAS Detector
Physical Review Letters 108:11 (2012)
Abstract:
A search for the Higgs boson has been performed in the H→WW( *)→+ν-ν̄ channel (=e/μ) with an integrated luminosity of 2.05fb-1 of pp collisions at √s=7TeV collected with the ATLAS detector at the Large Hadron Collider. No significant excess of events over the expected background is observed and limits on the Higgs boson production cross section are derived for a Higgs boson mass in the range 110GeVA measurement of the ratio of the W and Z cross sections with exactly one associated jet in pp collisions at s=7TeV with ATLAS
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 708:3-5 (2012) 221-240
Abstract:
The ratio of production cross sections of the W and Z bosons with exactly one associated jet is presented as a function of jet transverse momentum threshold. The measurement has been designed to maximise cancellation of experimental and theoretical uncertainties, and is reported both within a particle-level kinematic range corresponding to the detector acceptance and as a total cross-section ratio. Results are obtained with the ATLAS detector at the LHC in pp collisions at a centre-of-mass energy of 7 TeV using an integrated luminosity of 33 pb-1. The results are compared with perturbative leading-order, leading-log, and next-to-leading-order QCD predictions, and are found to agree within experimental and theoretical uncertainties. The ratio is measured for events with a single jet with pT>30 GeV to be 8.73±0.30(stat)±0.40(syst) in the electron channel, and 8.49±0.23(stat)±0.33(syst) in the muon channel. © 2012 CERN.Measurement of the production cross section for Z/γ* in association with jets in pp collisions at √s=7TeV with the ATLAS detector
Physical Review D - Particles, Fields, Gravitation and Cosmology 85:3 (2012)