| 1. |
- Aaron, F. D., et al.
(author)
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Combined measurement and QCD analysis of the inclusive e(+/-)p scattering cross sections at HERA
- 2010
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In: Journal of High Energy Physics. - 1029-8479. ; :1
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Journal article (peer-reviewed)abstract
- A combination is presented of the inclusive deep inelastic cross sections measured by the H1 and ZEUS Collaborations in neutral and charged current unpolarised e(+/-)p scattering at HERA during the period 1994-2000. The data span six orders of magnitude in negative four-momentum-transfer squared, Q(2), and in Bjorken x. The combination method used takes the correlations of systematic uncertainties into account, resulting in an improved accuracy. The combined data are the sole input in a NLO QCD analysis which determines a new set of parton distributions, HERAPDF1.0, with small experimental uncertainties. This set includes an estimate of the model and parametrisation uncertainties of the fit result.
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| 2. |
- Aaron, F. D., et al.
(author)
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A general search for new phenomena at HERA
- 2009
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In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 674:4-5, s. 257-268
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Journal article (peer-reviewed)abstract
- A model-independent search for deviations from the Standard Model prediction is performed using the full e(+/-) p data sample collected by the H1 experiment at HERA. All event topologies involving isolated electrons, photons, muons, neutrinos and jets with transverse momenta above 20 GeV are investigated in a single analysis. Events are assigned to exclusive classes according to their final state. A dedicated algorithm is used to search for deviations from the Standard Model in the distributions of the scalar sum of transverse momenta or the invariant mass of final state particles and to quantify their significance. Variables related to angular distributions and energy sharing between final state particles are also introduced to study the final state topologies. No significant deviation from the Standard Model expectation is observed in the phase space covered by this analysis. (C) 2009 Elsevier B.V. All rights reserved.
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| 3. |
- Aaroe, Lene, et al.
(author)
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The journalistic preference for extreme exemplars: educational socialization, psychological biases, or editorial policy?
- 2024
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In: JOURNAL OF COMMUNICATION. - 0021-9916 .- 1460-2466. ; 74:1, s. 48-62
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Journal article (peer-reviewed)abstract
- Exemplars are central in news reporting. However, extreme negative exemplars can bias citizens' factual perceptions and attributions of political responsibility. Nonetheless, our knowledge of the factors shaping journalistic preferences for including exemplars in news stories is limited. We investigate the extent to which educational socialization, psychological biases, and editorial policy shape journalistic preferences for extreme negative exemplars. We field large-scale survey experiments to a population sample of journalism students, a nationally representative sample of citizens, and a representative sample of "young people" and obtain evaluations of news value, newsworthiness, and behavioral measures of the actual write-up of news articles. We find significant support for the role of editorial policy and limited support for the role of educational socialization and psychological biases. In a time where economic pressures and the proliferation of digital media potentially lead editors to prioritize clickbait, these findings suggest that structural biases in news coverage may be aggravated.
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| 4. |
- Abramovich, Shoshana, et al.
(author)
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Some new estimates of the ‘Jensen gap’
- 2016
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In: Journal of inequalities and applications. - : Springer Science and Business Media LLC. - 1025-5834 .- 1029-242X. ; 2016
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Journal article (peer-reviewed)abstract
- Let (μ,Ω) be a probability measure space. We consider the so-called ‘Jensen gap’ J(φ,μ,f)=∫ Ω φ(f(s))dμ(s)−φ(∫ Ω f(s)dμ(s)) for some classes of functions φ. Several new estimates and equalities are derived and compared with other results of this type. Especially the case when φ has a Taylor expansion is treated and the corresponding discrete results are pointed out.
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| 5. |
- Aaron, F. D., et al.
(author)
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Combined inclusive diffractive cross sections measured with forward proton spectrometers in deep inelastic ep scattering at HERA
- 2012
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In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 72:10
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Journal article (peer-reviewed)abstract
- A combination of the inclusive diffractive cross section measurements made by the H1 and ZEUS Collaborations at HERA is presented. The analysis uses samples of diffractive deep inelastic ep scattering data at a centre-of-mass energy root s = 318 GeV where leading protons are detected by dedicated spectrometers. Correlations of systematic uncertainties are taken into account, resulting in an improved precision of the cross section measurement which reaches 6 % for the most precise points. The combined data cover the range 2.5 < Q(2) < 200 GeV2 in photon virtuality, 0.00035 < x(P) < 0.09 in proton fractional momentum loss, 0.09 < vertical bar t vertical bar < 0.55 GeV2 in squared four-momentum transfer at the proton vertex and 0.0018 < beta < 0.816 in beta = x/x(P), where x is the Bjorken scaling variable.
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| 6. |
- Aaron, F. D., et al.
(author)
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Measurement of dijet production in diffractive deep-inelastic scattering with a leading proton at HERA
- 2012
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In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 72:4
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Journal article (peer-reviewed)abstract
- The cross section of diffractive deep-inelastic scattering ep -> eXp is measured, where the system X contains at least two jets and the leading final state proton is detected in the H1 Forward Proton Spectrometer. The measurement is performed for fractional proton longitudinal momentum loss x(P) < 0.1 and covers the range 0.1 < vertical bar t vertical bar < 0.7 GeV2 in squared four-momentum transfer at the proton vertex and 4 < Q(2) < 110 GeV2 in photon virtuality. The differential cross sections extrapolated to vertical bar t vertical bar < 1 GeV2 are in agreement with next-to-leading order QCD predictions based on diffractive parton distribution functions extracted from measurements of inclusive and dijet cross sections in diffractive deep-inelastic scattering. The data are also compared with leading order Monte Carlo models.
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| 7. |
- Aaron, F. D., et al.
(author)
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Events with an isolated lepton and missing transverse momentum and measurement of W production at HERA
- 2010
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In: Journal of High Energy Physics. - 1029-8479. ; 2010:3, s. 1-19
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Journal article (peer-reviewed)abstract
- A search for events containing an isolated electron or muon and missing trans verse momentum produced in e(+/-)p collisions is performed with the H1 and ZEUS detectors at HERA. The data were taken in the period 1994-2007 and correspond to an integrated luminosity of 0.98 fb(-1). The observed event yields are in good overall agreement with the Standard Model prediction, which is dominated by single W production. In the e(+)p data, at large hadronic transverse momentum P-T(X) > 25GeV, a total of 23 events are observed compared to a prediction of 14.0 +/- 1.9. The total single W boson production cross section is measured as 1.06 +/- 0.16 (stat.) +/- 0.07 (sys.) pb, in agreement with an Standard Model (SM) expectation of 1.26 +/- 0.19 pb.
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| 8. |
- Aaron, F. D., et al.
(author)
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Measurement of the inclusive ep scattering cross section at low Q (2) and x at HERA
- 2009
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In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 63:4, s. 625-678
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Journal article (peer-reviewed)abstract
- A measurement of the inclusive ep scattering cross section is presented in the region of low momentum transfers, 0.2 GeV2 a parts per thousand currency signQ (2)a parts per thousand currency sign12 GeV2, and low Bjorken x, 5a <...10(-6)a parts per thousand currency signxa parts per thousand currency sign0.02. The result is based on two data sets collected in dedicated runs by the H1 Collaboration at HERA at beam energies of 27.6 GeV and 920 GeV for positrons and protons, respectively. A combination with data previously published by H1 leads to a cross section measurement of a few percent accuracy. A kinematic reconstruction method exploiting radiative ep events extends the measurement to lower Q (2) and larger x. The data are compared with theoretical models which apply to the transition region from photoproduction to deep inelastic scattering.
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| 9. |
- Aaron, F.D., et al.
(author)
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Charged particle production in high Q^2 deep-inelastic scattering at HERA
- 2007
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In: Physics Letters B. - : Elsevier BV. - 0370-2693. ; 654:5-6, s. 148-159
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Journal article (peer-reviewed)abstract
- The average charged track multiplicity and the normalised distribution of the scaled momentum, xp, of charged final state hadrons are measured in deep-inelastic ep scattering at high Q2 in the Breit frame of reference. The analysis covers the range of photon virtuality Click to view the MathML source. Compared with previous results presented by HERA experiments this analysis has a significantly higher statistical precision and extends the phase space to higher Q2 and to the full range of xp. The results are compared with e+e− annihilation data and with various calculations based on perturbative QCD using different models of the hadronisation process.
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| 10. |
- Aaron, F. D., et al.
(author)
-
Inclusive measurement of diffractive deep-inelastic scattering at HERA
- 2012
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In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 72:7
-
Journal article (peer-reviewed)abstract
- The diffractive process ep -> eXY, where Y denotes a proton or its low mass excitation with M-Y < 1.6 GeV, is studied with the H1 experiment at HERA. The analysis is restricted to the phase space region of the photon virtuality 3 <= Q(2) <= 1600 GeV2, the square of the fourmomentum transfer at the proton vertex vertical bar t vertical bar < 1.0 GeV2 and the longitudinal momentum fraction of the incident proton carried by the colourless exchange x(P) < 0.05. Triple differential cross sections are measured as a function of x(P), Q(2) and beta = x/x(P) where x is the Bjorken scaling variable. These measurements are made after selecting diffractive events by demanding a large empty rapidity interval separating the final state hadronic systems X and Y. High statistics measurements covering the data taking periods 1999-2000 and 2004-2007 are combined with previously published results in order to provide a single set of diffractive cross sections from the H1 experiment using the large rapidity gap selection method. The combined data represent a factor between three and thirty increase in statistics with respect to the previously published results. The measurements are compared with predictions from NLO QCD calculations based on diffractive parton densities and from a dipole model. The proton vertex factorisation hypothesis is tested.
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