SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Hansen Thomas V. O.) "

Sökning: WFRF:(Hansen Thomas V. O.)

Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
61.
  • Aad, G., et al. (författare)
  • Search for the Standard Model Higgs boson in the two photon decay channel with the ATLAS detector at the LHC
  • 2011
  • Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier. - 0370-2693 .- 1873-2445. ; 705:5, s. 452-470
  • Tidskriftsartikel (refereegranskat)abstract
    • A search for the Standard Model Higgs boson in the two photon decay channel is reported, using 1.08 fb(-1) of proton-proton collision data at a centre-of-mass energy of 7 TeV recorded by the ATLAS detector. No significant excess is observed in the investigated mass range of 110-150 GeV. Upper limits on the cross-section,times branching ratio of between 2.0 and 5.8 times the Standard Model prediction are derived for this mass range. (C) 2011 CERN. Published by Elsevier B.V. All rights reserved.
  •  
62.
  • Aad, G., et al. (författare)
  • Limits on the production of the standard model Higgs boson in pp collisions at root s=7 TeV with the ATLAS detector
  • 2011
  • Ingår i: European Physical Journal C. Particles and Fields. - : Springer. - 1434-6044 .- 1434-6052. ; 71:9
  • Tidskriftsartikel (refereegranskat)abstract
    • A search for the Standard Model Higgs boson at the Large Hadron Collider (LHC) running at a centre-of-mass energy of 7 TeV is reported, based on a total integrated luminosity of up to 40 pb(-1) collected by the ATLAS detector in 2010. Several Higgs boson decay channels: H -> gamma gamma, H -> ZZ(()*()) -> llll, H -> ZZ -> LL nu nu, H -> ZZ -> llqq, H -> WW(*()) -> l nu l nu and H -> WW -> l nu qq (l is e, mu) are combined in a mass range from 110 GeV to 600 GeV. The highest sensitivity is achieved in the mass range between 160 GeV and 170 GeV, where the expected 95% CL exclusion sensitivity is at Higgs boson production cross sections 2.3 times the Standard Model prediction. Upper limits on the cross section for its production are determined. Models with a fourth generation of heavy leptons and quarks with Standard Model-like couplings to the Higgs boson are also investigated and are excluded at 95% CL for a Higgs boson mass in the range from 140 GeV to 185 GeV.
  •  
63.
  • Aad, G., et al. (författare)
  • Measurement of inclusive two-particle angular correlations in pp collisions with the ATLAS detector at the LHC
  • 2012
  • Ingår i: Journal of High Energy Physics. - : Springer. - 1029-8479 .- 1126-6708. ; :5
  • Tidskriftsartikel (refereegranskat)abstract
    • We present a measurement of two-particle angular correlations in proton-proton collisions at root s = 900 GeV and 7 TeV. The collision events were collected during 2009 and 2010 with the ATLAS detector at the Large Hadron Collider using a single-arm minimum bias trigger. Correlations are measured for charged particles produced in the kinematic range of transverse momentum p(T) > 100 MeV and pseudorapidity vertical bar eta vertical bar < 2.5. A complex structure in pseudorapidity and azimuth is observed at both collision energies. Results are compared to PYTHIA 8 and HERWIG++ as well as to the AMBT2B, DW and Perugia 2011 tunes of PYTHIA 6. The data are not satisfactorily described by any of these models.
  •  
64.
  • Aad, G., et al. (författare)
  • Measurement of the cross-section for b-jets produced in association with a Z boson at root s=7 TeV with the ATLAS detector ATLAS Collaboration
  • 2012
  • Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier. - 0370-2693 .- 1873-2445. ; 706:4-5, s. 295-313
  • Tidskriftsartikel (refereegranskat)abstract
    • A measurement is presented of the inclusive cross-section for b-jet production in association with a Z boson in pp collisions at a centre-of-mass energy of root s = 7 TeV. The analysis uses the data sample collected by the ATLAS experiment in 2010, corresponding to an integrated luminosity of approximately 36 pb(-1). The event selection requires a Z boson decaying into high P-T electrons or muons, and at least one b-jet, identified by its displaced vertex, with transverse momentum p(T) > 25 GeV and rapidity vertical bar y vertical bar < 2.1. After subtraction of background processes, the yield is extracted from the vertex mass distribution of the candidate b-jets. The ratio of this cross-section to the inclusive Z cross-section (the average number of b-jets per Z event) is also measured. Both results are found to be in good agreement with perturbative QCD predictions at next-to-leading order. (C) 2011 CERN. Published by Elsevier B.V. All rights reserved.
  •  
65.
  • Aad, G., et al. (författare)
  • Measurement of the gamma(1S) production cross-section in pp collisions at root s=7 TeV in ATLAS ATLAS Collaboration
  • 2011
  • Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier. - 0370-2693 .- 1873-2445. ; 705:1–2, s. 9-27
  • Tidskriftsartikel (refereegranskat)abstract
    • A measurement of the cross-section for ϒ ( 1 S ) → μ + μ − production in proton–proton collisions at centre of mass energy of 7 TeV is presented. The cross-section is measured as a function of the ϒ ( 1 S ) transverse momentum in two bins of rapidity, | y ϒ ( 1 S ) | < 1.2 and 1.2 < | y ϒ ( 1 S ) | < 2.4 . The measurement requires that both muons have transverse momentum p T μ > 4 GeV and pseudorapidity | η μ | < 2.5 in order to reduce theoretical uncertainties on the acceptance, which depend on the poorly known polarisation. The results are based on an integrated luminosity of 1.13 pb−1, collected with the ATLAS detector at the Large Hadron Collider. The cross-section measurement is compared to theoretical predictions: it agrees to within a factor of two with a prediction based on the NRQCD model including colour-singlet and colour-octet matrix elements as implemented in Pythia while it disagrees by up to a factor of ten with the next-to-leading order prediction based on the colour-singlet model.
  •  
66.
  • Aad, G., et al. (författare)
  • Measurement of the inclusive isolated prompt photon cross section in pp collisions at root s=7 TeV with the ATLAS detector
  • 2011
  • Ingår i: Physical Review D (Particles, Fields, Gravitation and Cosmology). - : American Physical Society. - 1550-2368 .- 1550-7998. ; 83:5
  • Tidskriftsartikel (refereegranskat)abstract
    • A measurement of the cross section for the inclusive production of isolated prompt photons in pp collisions at a center-of-mass energy root s = 7 TeV is presented. The measurement covers the pseudorapidity ranges vertical bar eta(gamma)vertical bar < 1: 37 and 1: 52 <= vertical bar eta(gamma)vertical bar < 1: 81 in the transverse energy range 15 <= E-T(gamma) < 100 GeV. The results are based on an integrated luminosity of 880 nb(-1), collected with the ATLAS detector at the Large Hadron Collider. Photon candidates are identified by combining information from the calorimeters and from the inner tracker. Residual background in the selected sample is estimated from data based on the observed distribution of the transverse isolation energy in a narrow cone around the photon candidate. The results are compared to predictions from next-to-leading-order perturbative QCD calculations.
  •  
67.
  • Aad, G., et al. (författare)
  • Measurement of the production cross section for W-bosons in association with jets in pp collisions at root s=7 TeV with the ATLAS detector
  • 2011
  • Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier. - 0370-2693 .- 1873-2445. ; 698:5, s. 325-345
  • Tidskriftsartikel (refereegranskat)abstract
    • This Letter reports on a first measurement of the inclusive W + jets cross section in proton-proton collisions at a centre-of-mass energy of 7 TeV at the LHC, with the ATLAS detector. Cross sections, in both the electron and muon decay modes of the W-boson, are presented as a function of jet multiplicity and of the transverse momentum of the leading and next-to-leading jets in the event. Measurements are also presented of the ratio of cross sections sigma (W + >= n)/sigma(W + >= n - 1) for inclusive jet multiplicities n = 1-4. The results, based on an integrated luminosity of 1.3 pb(-1), have been corrected for all known detector effects and are quoted in a limited and well-defined range of jet and lepton kinematics. The measured cross sections are compared to particle-level predictions based on perturbative QCD. Next-to-leading order calculations, studied here for n <= 2, are found in good agreement with the data. Leading-order multiparton event generators, normalized to the NNLO total cross section, describe the data well for all measured jet multiplicities. (C) 2011 CERN. Published by Elsevier B.V. All rights reserved.
  •  
68.
  • Aad, G., et al. (författare)
  • Measurement of the production cross section of an isolated photon associated with jets in proton-proton collisions at root s=7 TeV with the ATLAS detector
  • 2012
  • Ingår i: Physical Review D (Particles, Fields, Gravitation and Cosmology). - : American Physical Society. - 1550-2368 .- 1550-7998. ; 85:9
  • Tidskriftsartikel (refereegranskat)abstract
    • A measurement of the cross section for the production of an isolated photon in association with jets in proton-proton collisions at a center-of-mass energy root s = 7 TeV is presented. Photons are reconstructed in the pseudorapidity range vertical bar eta(gamma)vertical bar < 1.37 and with a transverse energy E-T(gamma) > 25 GeV. Jets are reconstructed in the rapidity range vertical bar y(jet)vertical bar < 4.4 and with a transverse momentum p(T)(jet) > 20 GeV. The differential cross section d sigma/dE(T)(gamma) is measured, as a function of the photon transverse energy, for three different rapidity ranges of the leading-p(T) jet: vertical bar y(jet)vertical bar < 1.2, 1.2 <= vertical bar y(jet)vertical bar < 2.8 and 2.8 <= vertical bar y(jet)vertical bar < 4.4. For each rapidity configuration the same-sign (eta(gamma)y(jet) >= 0) and opposite-sign (eta(gamma) y(jet) < 0) cases are studied separately. The results are based on an integrated luminosity of 37 pb(-1), collected with the ATLAS detector at the LHC. Next-to-leading order perturbative QCD calculations are found to be in fair agreement with the data, except for E-T(gamma) <= 45 GeV, where the theoretical predictions overestimate the measured cross sections.
  •  
69.
  • Aad, G., et al. (författare)
  • Observation of a Centrality-Dependent Dijet Asymmetry in Lead-Lead Collisions at root s(NN)=2.76 TeV with the ATLAS Detector at the LHC
  • 2010
  • Ingår i: Physical Review Letters. - : American Physical Society. - 1079-7114 .- 0031-9007. ; 105:25
  • Tidskriftsartikel (refereegranskat)abstract
    • By using the ATLAS detector, observations have been made of a centrality-dependent dijet asymmetry in the collisions of lead ions at the Large Hadron Collider. In a sample of lead-lead events with a per-nucleon center of mass energy of 2.76 TeV, selected with a minimum bias trigger, jets are reconstructed in fine-grained, longitudinally segmented electromagnetic and hadronic calorimeters. The transverse energies of dijets in opposite hemispheres are observed to become systematically more unbalanced with increasing event centrality leading to a large number of events which contain highly asymmetric dijets. This is the first observation of an enhancement of events with such large dijet asymmetries, not observed in proton-proton collisions, which may point to an interpretation in terms of strong jet energy loss in a hot, dense medium.
  •  
70.
  • Aad, G., et al. (författare)
  • Observation of a New X-b State in Radiative Transitions to Y(1S) and Y(2S) at ATLAS
  • 2012
  • Ingår i: Physical Review Letters. - : American Physical Society. - 1079-7114. ; 108:15
  • Tidskriftsartikel (refereegranskat)abstract
    • The chi(b)(np) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider at root s=7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb(-1), these states are reconstructed through their radiative decays to Y(1S,2S) with Y ->mu(+)mu(-). In addition to the mass peaks corresponding to the decay modes chi(b)(1P,2P)-> Y(1S)gamma, a new structure centered at a mass of 10.530 +/- 0.005(stat)+/- 0.009(syst) GeV is also observed, in both the Y(1S)gamma and Y(2S)gamma decay modes. This structure is interpreted as the chi(b)(3P) system.
  •  
Skapa referenser, mejla, bekava och länka
Typ av publikation
tidskriftsartikel (729)
forskningsöversikt (8)
konferensbidrag (1)
Typ av innehåll
refereegranskat (737)
övrigt vetenskapligt (1)
Författare/redaktör
Aad, G (568)
Yang, H. (559)
Zhang, X. (552)
Zhu, H. (528)
Li, S. (515)
Lee, S. C. (514)
visa fler...
Zwalinski, L. (510)
Zhang, H. (510)
Jia, J. (508)
Milov, A. (508)
Tojo, J. (507)
Zhu, J. (505)
Jinnouchi, O. (500)
Wang, H. (490)
Yang, Y. (489)
Kim, S. H. (487)
Kobayashi, T. (487)
Liu, Y. (487)
Hill, J. C. (484)
Bauer, F. (483)
Arai, Y. (475)
Nagasaka, Y. (475)
Chen, X. (474)
Vrba, V. (473)
Zhang, J. (473)
Schumacher, M. (472)
Chen, H. (471)
Ferrer, A. (470)
Garcia, C. (470)
Nilsson, P. (470)
Blumenschein, U. (469)
Boonekamp, M. (469)
Eigen, G. (469)
Ekelof, T. (469)
Fassouliotis, D. (469)
Francis, D. (469)
Hamacher, K. (469)
Kourkoumelis, C. (469)
Leitner, R. (469)
Li, H. (469)
Liebig, W. (469)
Meyer, J. (469)
Ouraou, A. (469)
Quadt, A. (469)
Salt, J. (469)
Stugu, B. (469)
Tanaka, S. (469)
Vachon, B. (469)
Wang, J. (469)
Masik, J. (469)
visa färre...
Lärosäte
Lunds universitet (673)
Kungliga Tekniska Högskolan (413)
Uppsala universitet (41)
Karolinska Institutet (39)
Umeå universitet (31)
Göteborgs universitet (19)
visa fler...
Stockholms universitet (18)
Linköpings universitet (15)
Chalmers tekniska högskola (8)
Jönköping University (3)
Örebro universitet (1)
Mittuniversitetet (1)
visa färre...
Språk
Engelska (738)
Forskningsämne (UKÄ/SCB)
Naturvetenskap (632)
Medicin och hälsovetenskap (89)
Teknik (2)
Humaniora (1)

År

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy