44 research outputs found

    Impact of jet-production data on the next-to-next-to-leading-order determination of HERAPDF2.0 parton distributions

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    The HERAPDF2.0 ensemble of parton distribution functions (PDFs) was introduced in 2015. The final stage is presented, a next-to-next-to-leading-order (NNLO) analysis of the HERA data on inclusive deep inelastic ep scattering together with jet data as published by the H1 and ZEUS collaborations. A perturbative QCD fit, simultaneously of αs(M2Z) and the PDFs, was performed with the result αs(M2Z)=0.1156±0.0011 (exp) +0.0001−0.0002 (model +parameterisation) ±0.0029 (scale). The PDF sets of HERAPDF2.0Jets NNLO were determined with separate fits using two fixed values of αs(M2Z), αs(M2Z)=0.1155 and 0.118, since the latter value was already chosen for the published HERAPDF2.0 NNLO analysis based on HERA inclusive DIS data only. The different sets of PDFs are presented, evaluated and compared. The consistency of the PDFs determined with and without the jet data demonstrates the consistency of HERA inclusive and jet-production cross-section data. The inclusion of the jet data reduced the uncertainty on the gluon PDF. Predictions based on the PDFs of HERAPDF2.0Jets NNLO give an excellent description of the jet-production data used as input

    Impact of jet-production data on the next-to-next-to-leading-order determination of HERAPDF2.0 parton distributions

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    International audienceThe HERAPDF2.0 ensemble of parton distribution functions (PDFs) was introduced in 2015. The final stage is presented, a next-to-next-to-leading-order (NNLO) analysis of the HERA data on inclusive deep inelastic ep scattering together with jet data as published by the H1 and ZEUS collaborations. A perturbative QCD fit, simultaneously of αs(MZ2)\alpha _s(M_Z^2) and the PDFs, was performed with the result αs(MZ2)=0.1156±0.0011 (exp) 0.0002+0.0001 (model+parameterisation) ±0.0029 (scale)\alpha _s(M_Z^2)= 0.1156 \pm 0.0011~\mathrm{(exp)}~ ^{+0.0001}_{-0.0002}~ \mathrm{(model}\mathrm{+ parameterisation)}~ \pm 0.0029~\mathrm{(scale)}. The PDF sets of HERAPDF2.0Jets NNLO were determined with separate fits using two fixed values of αs(MZ2)\alpha _s(M_Z^2), αs(MZ2)=0.1155\alpha _s(M_Z^2)=0.1155 and 0.118, since the latter value was already chosen for the published HERAPDF2.0 NNLO analysis based on HERA inclusive DIS data only. The different sets of PDFs are presented, evaluated and compared. The consistency of the PDFs determined with and without the jet data demonstrates the consistency of HERA inclusive and jet-production cross-section data. The inclusion of the jet data reduced the uncertainty on the gluon PDF. Predictions based on the PDFs of HERAPDF2.0Jets NNLO give an excellent description of the jet-production data used as input

    Combination and QCD analysis of charm production cross section measurements in deep-inelastic ep scattering at HERA

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    Measurements of open charm production cross sections in deep-inelastic ep scattering at HERA from the H1 and ZEUS Collaborations are combined. Reduced cross sections sigma(c (c) over bar)(red) for charm production are obtained in the kinematic range of photon virtuality 2.5 LT = Q(2) LT = 2000 GeV2 and Bjorken scaling variable 3 . 10(-5) LT = x LT = 5 . 10(-2). The combination method accounts for the correlations of the systematic uncertainties among the different data sets. The combined charm data together with the combined inclusive deep-inelastic scattering cross sections from HERA are used as input for a detailed NLO QCD analysis to study the influence of different heavy flavour schemes on the parton distribution functions. The optimal values of the charm mass as a parameter in these different schemes are obtained. The implications on the NLO predictions for W-+/- and Z production cross sections at the LHC are investigated. Using the fixed flavour number scheme, the running mass of the charm quark is determined

    Effectiveness of systemic high-dose dexamethasone therapy for idiopathic sudden sensorineural hearing loss.

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    Objective: To evaluate the effectiveness of systemic high-dose dexamethasone therapy for sudden sensorineural hearing loss in comparison to the previous treatment regimen at our clinic with systemic prednisone 100 mg daily for 7 days analyzed in a previous study. Methods: We conducted a retrospective review of an electronic patient data base of 79 patients with idiopathic sudden sensorineural hearing loss. The standard treatment was orally applied dexamethasone (1st to 3rd day: 40 mg daily, 4th to 6th day: 10 mg daily) in an ambulant setting. The primary endpoint was change in hearing threshold from the initial audiogram to an audiogram at least 4 weeks later. Factors that were analyzed included patient's age, interval between onset of symptoms and start of treatment, presence or absence of dizziness and tinnitus, the audiogram pattern, severity of hearing loss and hearing in the opposite ear. Hearing gain was expressed either as absolute or relative hearing gain. Functionally relevant recovery of hearing was defined as the final pure-tone average (PTA) of 30 dB or less (or the same as the PTA of the opposite ear ± 10 dB). Furthermore, we calculated the percentage of patients with complete, partial and no recovery as defined in the recently published Clinical Practice Guideline of the American Academy of Otolaryngology - Head and Neck Surgery Foundation. We then compared our results with the previous treatment regimen carried out at our clinic. Results: The average initial PTA hearing loss in the affected ear compared to baseline PTA of the unaffected ear was 51.5 ± 20.9 dB (mean ± SD). The mean absolute hearing gain was 44.4 ± 18.1 dB. The mean relative hearing gain was 86 ± 19%. Of the total, 87% had functionally relevant recovery of hearing. All of our patients showed partial (24%) or complete recovery (76%). No difference in recovery rate could be detected between patients with start of therapy within 24 h and patients with beginning of therapy within 7 days. We found a correlation between the severity of hearing loss and functionally relevant recovery. A mild hearing loss was noted in 34% of patients, with an average relative hearing gain of 89% and a functionally relevant recovery in 96% of them; the 9% of patients with initial deafness showed a mean relative hearing gain of 69% and a functionally relevant recovery in 43%. The audiogram pattern with low- or high-frequency hearing loss showed the best recovery rate; the poorest recovery rate was found in patients with initial deafness. Conclusion: Application of high-dose orally applied dexamethasone seems to improve the recovery outcomes in comparison to prednisone 100 mg p.o. for 7 days

    Virtue ethics and social psychology

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    Virtue ethics has emerged as an alternative to deontological and utilitarian theory in recent moral philosophy. The basic notion of virtue ethics is to reassert the importance of virtuous character in ethical judgement in contrast to the emphasis on principles and consequences. Since questions of virtue have been largely neglected in modern moral theory, there has been a return to Aristotle’s account of virtue as character. This in turn has been questioned as the basis of virtue ethics and there has been a search for alternative accounts of moral agency. One aspect of this critical reflection on virtue ethics is an engagement with social psychology as a source of criticism of the Aristotelian conception of character and as a more plausible alternative foundation for a theory of moral character with contemporary relevance. This paper aims to introduce this area of moral theory to a psychological audience and reflect on the interpretation of social psychological theory and evidence in criticisms of virtuous character, focusing on the use of Milgram’s (1974) experiments on obedience to authority as an argument for situationism. A number of questions emerge concerning the interpretation and use of social psychological theory and evidence in debates within moral philosophy
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