SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Nilsson E.) "

Sökning: WFRF:(Nilsson E.)

Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
21.
  • Aad, G., et al. (författare)
  • Jet mass and substructure of inclusive jets in root s=7 TeV pp collisions with the ATLAS experiment
  • 2012
  • Ingår i: Journal of High Energy Physics. - : Springer. - 1029-8479 .- 1126-6708. ; :5
  • Tidskriftsartikel (refereegranskat)abstract
    • Recent studies have highlighted the potential of jet substructure techniques to identify the hadronic decays of boosted heavy particles. These studies all rely upon the assumption that the internal substructure of jets generated by QCD radiation is well understood. In this article, this assumption is tested on an inclusive sample of jets recorded with the ATLAS detector in 2010, which corresponds to 35 pb(-1) of pp collisions delivered by the LHC at root s = 7 TeV. In a subsample of events with single pp collisions, measurements corrected for detector efficiency and resolution are presented with full systematic uncertainties. Jet invariant mass, k(t) splitting scales and N-subjettiness variables are presented for anti-k(t) R = 1.0 jets and Cambridge-Aachen R = 1.2 jets. Jet invariant-mass spectra for Cambridge-Aachen R = 1.2 jets after a splitting and filtering procedure are also presented. Leading-order parton-shower Monte Carlo predictions for these variables are found to be broadly in agreement with data. The dependence of mean jet mass on additional pp interactions is also explored.
  •  
22.
  • Aad, G., et al. (författare)
  • Measurement of the centrality dependence of the charged particle pseudorapidity distribution in lead-lead collisions at root s(NN)=2.76 TeV with the ATLAS detector
  • 2012
  • Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier. - 0370-2693 .- 1873-2445. ; 710:3, s. 363-382
  • Tidskriftsartikel (refereegranskat)abstract
    • The ATLAS experiment at the LHC has measured the centrality dependence of charged particle pseudorapidity distributions over vertical bar eta vertical bar < 2 in lead-lead collisions at a nucleon-nucleon centre-of-mass energy of root s(NN) = 2.76 TeV. In order to include particles with transverse momentum as low as 30 MeV, the data were recorded with the central solenoid magnet off. Charged particles were reconstructed with two algorithms (2-point "tracklets" and full tracks) using information from the pixel detector only. The lead-lead collision centrality was characterized by the total transverse energy in the forward calorimeter in the range 3.2 < vertical bar eta vertical bar< 4.9. Measurements are presented of the per-event charged particle pseudorapidity distribution, dN(ch)/d eta, and the average charged particle multiplicity in the pseudorapidity interval vertical bar eta vertical bar < 0.5 in several intervals of collision centrality. The results are compared to previous mid-rapidity measurements at the LHC and RHIC. The variation of the mid-rapidity charged particle yield per colliding nucleon pair with the number of participants is consistent with lower root s(NN) results. The shape of the dN(ch)/d eta distribution is found to be independent of centrality within the systematic uncertainties of the measurement. (C) 2012 CERN. Published by Elsevier B.V. All rights reserved.
  •  
23.
  • Aad, G., et al. (författare)
  • Observation of Spin Correlation in t(t)over-bar Events from pp Collisions at root s=7 TeV Using the ATLAS Detector
  • 2012
  • Ingår i: Physical Review Letters. - : American Physical Society. - 1079-7114 .- 0031-9007. ; 108:21
  • Tidskriftsartikel (refereegranskat)abstract
    • A measurement of spin correlation in t (t) over bar production is reported using data collected with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 2.1 fb(-1). Candidate events are selected in the dilepton topology with large missing transverse energy and at least two jets. The difference in azimuthal angle between the two charged leptons in the laboratory frame is used to extract the correlation between the top and antitop quark spins. In the helicity basis the measured degree of correlation corresponds to A(helicity) = 0.40(-0.08)(+0.09), in agreement with the next-to-leading-order standard model prediction. The hypothesis of zero spin correlation is excluded at 5.1 standard deviations.
  •  
24.
  • Aad, G., et al. (författare)
  • Search for extra dimensions using diphoton events in 7 TeV proton-proton collisions 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. ; 710:4-5, s. 538-556
  • Tidskriftsartikel (refereegranskat)abstract
    • Using data recorded in 2011 with the ATLAS detector at the Large Hadron Collider, a search for evidence of extra spatial dimensions has been performed through an analysis of the diphoton final state. The analysis uses data corresponding to an integrated luminosity of 2.12 fb(-1) of root s = 7 TeV proton-proton collisions. The diphoton invariant mass (m(gamma gamma)) spectrum is observed to be in good agreement with the expected Standard Model background. In the large extra dimension scenario of Arkani-Hamed, Dimopoulos and Dvali, the results provide 95% CL lower limits on the fundamental Planck scale between 2.27 and 3.53 TeV, depending on the number of extra dimensions and the theoretical formalism used. The results also set 95% CL lower limits on the lightest Randall-Sundrum graviton mass of between 0.79 and 1.85 TeV, for values of the dimensionless coupling k/(M) over bar (Pl) varying from 0.01 to 0.1. Combining with previously published ATLAS results from the dielectron and dimuon final states, the 95% CL lower limit on the Randall-Sundrum graviton mass for k/(M) over bar (Pl) = 0.01 (0.1) is 0.80 (1.95) TeV. (C) 2012 CERN. Published by Elsevier B.V. All rights reserved.
  •  
25.
  • Aad, G., et al. (författare)
  • Search for New Particles in Two-Jet Final States in 7 TeV Proton-Proton Collisions with the ATLAS Detector at the LHC
  • 2010
  • Ingår i: Physical Review Letters. - : American Physical Society. - 1079-7114 .- 0031-9007. ; 105:16
  • Tidskriftsartikel (refereegranskat)abstract
    • A search for new heavy particles manifested as resonances in two-jet final states is presented. The data were produced in 7 TeV proton-proton collisions by the LHC and correspond to an integrated luminosity of 315 nb(-1) collected by the ATLAS detector. No resonances were observed. Upper limits were set on the product of cross section and signal acceptance for excited-quark (q*) production as a function of q* mass. These exclude at the 95% C. L. the q* mass interval 0: 30< m(q)*< 1:26 TeV, extending the reach of previous experiments.
  •  
26.
  • Aad, G., et al. (författare)
  • Searches for heavy long-lived sleptons and R-hadrons with the ATLAS detector in pp collisions at root s=7 TeV
  • 2013
  • Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier. - 0370-2693 .- 1873-2445. ; 720:4-5, s. 277-308
  • Tidskriftsartikel (refereegranskat)abstract
    • A search for long-lived particles is performed using a data sample of 4.7 fb(-1) from proton-proton collisions at a centre-of-mass energy. root s = 7 TeV collected by the ATLAS detector at the LHC. No excess is observed above the estimated background and lower limits, at 95% confidence level, are set on the mass of the long-lived particles in different scenarios, based on their possible interactions in the inner detector, the calorimeters and the muon spectrometer. Long-lived staus in gauge-mediated SUSY-breaking models are excluded up to a mass of 300 GeV for tan beta = 5-20. Directly produced long-lived sleptons are excluded up to a mass of 278 GeV. R-hadrons, composites of gluino (stop, sbottom) and light quarks, are excluded up to a mass of 985 GeV (683 GeV, 612 GeV) when using a generic interaction model. Additionally two sets of limits on R-hadrons are obtained that are less sensitive to the interaction model for R-hadrons. One set of limits is obtained using only the inner detector and calorimeter observables, and a second set of limits is obtained based on the inner detector alone. (c) 2013 CERN. Published by Elsevier B.V. All rights reserved.
  •  
27.
  • Aad, G., et al. (författare)
  • Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC
  • 2013
  • Ingår i: European Physical Journal C. Particles and Fields. - : Springer. - 1434-6044 .- 1434-6052. ; 73:3
  • Tidskriftsartikel (refereegranskat)abstract
    • The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of root s = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K-s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5 % for central isolated hadrons and 1-3 % for the final calorimeter jet energy scale.
  •  
28.
  • Aad, G, et al. (författare)
  • ATLAS Run 1 searches for direct pair production of third-generation squarks at the Large Hadron Collider.
  • 2015
  • Ingår i: European Physical Journal C. Particles and Fields. - : Springer. - 1434-6044 .- 1434-6052. ; 75:10
  • Tidskriftsartikel (refereegranskat)abstract
    • This paper reviews and extends searches for the direct pair production of the scalar supersymmetric partners of the top and bottom quarks in proton-proton collisions collected by the ATLAS collaboration during the LHC Run 1. Most of the analyses use 20 [Formula: see text] of collisions at a centre-of-mass energy of [Formula: see text] TeV, although in some case an additional [Formula: see text] of collision data at [Formula: see text] TeV are used. New analyses are introduced to improve the sensitivity to specific regions of the model parameter space. Since no evidence of third-generation squarks is found, exclusion limits are derived by combining several analyses and are presented in both a simplified model framework, assuming simple decay chains, as well as within the context of more elaborate phenomenological supersymmetric models.
  •  
29.
  • Aad, G., et al. (författare)
  • Constraints on new phenomena via Higgs boson couplings and invisible decays with the ATLAS detector
  • 2015
  • Ingår i: Journal of High Energy Physics. - : Springer. - 1029-8479 .- 1126-6708. ; :11
  • Tidskriftsartikel (refereegranskat)abstract
    • The ATLAS experiment at the LHC has measured the Higgs boson couplings and mass, and searched for invisible Higgs boson decays, using multiple production and decay channels with up to 4.7 fb(-1) of pp collision data at root S = 7 TeV and 20.3 fb(-1) at root s = 8 TeV. In the current study, the measured production and decay rates of the observed Higgs boson in the gamma gamma, ZZ, WW, Z gamma, bb, tau tau, and mu mu decay channels, along with results from the associated production of a Higgs boson with a top-quark pair, are used to probe the scaling of the couplings with mass. Limits are set on parameters in extensions of the Standard Model including a composite Higgs boson, an additional electroweak singlet, and two-Higgs-doublet models. Together with the measured mass of the scalar Higgs boson in the gamma gamma and ZZ decay modes, a lower limit is set on the pseudoscalar Higgs boson mass of m(A) > 370 GeV in the "hMSSM" simplified Minimal Supersymmetric Standard Model. Results from direct searches for heavy Higgs bosons are also interpreted in the hMSSM. Direct searches for invisible Higgs boson decays in the vector-boson fusion and associated production of a Higgs boson with W/Z (Z -> ll, W/Z -> jj) modes are statistically combined to set an upper limit on the Higgs boson invisible branching ratio of 0.25. The use of the measured visible decay rates in a more general coupling fit improves the upper limit to 0.23, constraining a Higgs portal model of dark matter.
  •  
30.
  • Aad, G., et al. (författare)
  • Luminosity determination in pp collisions at root s=7 TeV using the ATLAS detector at the LHC
  • 2011
  • Ingår i: European Physical Journal C. Particles and Fields. - : Springer. - 1434-6044 .- 1434-6052. ; 71:4
  • Tidskriftsartikel (refereegranskat)abstract
    • Measurements of luminosity obtained using the ATLAS detector during early running of the Large Hadron Collider (LHC) at root s = 7 TeV are presented. The luminosity is independently determined using several detectors and multiple algorithms, each having different acceptances, systematic uncertainties and sensitivity to background. The ratios of the luminosities obtained from these methods are monitored as a function of time and of mu, the average number of inelastic interactions per bunch crossing. Residual time- and mu-dependence between the methods is less than 2% for 0 < mu < 2.5. Absolute luminosity calibrations, performed using beam separation scans, have a common systematic uncertainty of +/- 11%, dominated by the measurement of the LHC beam currents. After calibration, the luminosities obtained from the different methods differ by at most +/- 2%. The visible cross sections measured using the beam scans are compared to predictions obtained with the PYTHIA and PHOJET event generators and the ATLAS detector simulation.
  •  
Skapa referenser, mejla, bekava och länka
Typ av publikation
tidskriftsartikel (3634)
konferensbidrag (480)
bokkapitel (59)
forskningsöversikt (56)
rapport (47)
annan publikation (43)
visa fler...
doktorsavhandling (32)
bok (6)
samlingsverk (redaktörskap) (5)
patent (2)
proceedings (redaktörskap) (1)
recension (1)
visa färre...
Typ av innehåll
refereegranskat (3757)
övrigt vetenskapligt (569)
populärvet., debatt m.m. (40)
Författare/redaktör
Aad, G (570)
Lee, S. C. (533)
Zwalinski, L. (510)
Kim, S. H. (506)
Jia, J. (497)
Ferrari, P. (488)
visa fler...
Jinnouchi, O. (487)
Arai, Y. (476)
Chen, H. (475)
Borisov, A. (473)
Hill, J. C. (473)
Backes, M. (472)
Chen, X. (472)
Li, S. (472)
Hughes, G. (471)
Dris, M. (470)
Ferrer, A. (470)
Kobayashi, T. (470)
Bauer, F. (469)
D'Onofrio, M. (469)
Davies, M. (469)
Evans, H. (469)
Francis, D. (469)
Gagliardi, G. (469)
Guyot, C. (469)
Li, H. (469)
Antonelli, M. (468)
Bella, G. (468)
Benekos, N. (468)
Bentvelsen, S. (468)
Blumenschein, U. (468)
Boonekamp, M. (468)
Calderini, G. (468)
Campana, S. (468)
Cowan, G. (468)
Cranmer, K. (468)
Dallapiccola, C. (468)
Eigen, G. (468)
Ekelof, T. (468)
Etzion, E. (468)
Fassouliotis, D. (468)
Fleck, I. (468)
Garcia, C. (468)
Gross, E. (468)
Hamacher, K. (468)
Ishino, M. (468)
Kawagoe, K. (468)
Kawamoto, T. (468)
Kourkoumelis, C. (468)
Leitner, R. (468)
visa färre...
Lärosäte
Lunds universitet (1454)
Karolinska Institutet (1030)
Uppsala universitet (696)
Kungliga Tekniska Högskolan (675)
Göteborgs universitet (479)
Stockholms universitet (364)
visa fler...
Umeå universitet (342)
Linköpings universitet (273)
Chalmers tekniska högskola (256)
Linnéuniversitetet (94)
Örebro universitet (93)
Mittuniversitetet (59)
Karlstads universitet (52)
RISE (44)
Jönköping University (39)
Sveriges Lantbruksuniversitet (38)
Blekinge Tekniska Högskola (29)
Luleå tekniska universitet (28)
Högskolan i Borås (20)
Malmö universitet (19)
Högskolan Kristianstad (17)
Mälardalens högskola (15)
Södertörns högskola (13)
Högskolan i Gävle (12)
Högskolan Dalarna (12)
Högskolan Väst (11)
Högskolan i Skövde (11)
Gymnastik- och idrottshögskolan (11)
Högskolan i Halmstad (9)
VTI - Statens väg- och transportforskningsinstitut (5)
Ersta Sköndal Bräcke högskola (4)
Sophiahemmet Högskola (4)
Konstfack (3)
Naturhistoriska riksmuseet (3)
Röda Korsets Högskola (3)
Naturvårdsverket (1)
visa färre...
Språk
Engelska (4274)
Svenska (77)
Odefinierat språk (13)
Tyska (1)
Danska (1)
Forskningsämne (UKÄ/SCB)
Medicin och hälsovetenskap (1451)
Naturvetenskap (1422)
Samhällsvetenskap (220)
Teknik (208)
Lantbruksvetenskap (52)
Humaniora (17)

År

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy