Measurement of the open-charm contribution to the diffractive proton structure function

Production of D*+/-(2010) mesons in diffractive deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 82 pb^{-1}. Diffractive events were identified by the presence of a large rapidity gap in the final state. Differential cross sections have been measured in the kinematic region 1.5 < Q^2 < 200 GeV^2, 0.02 < y < 0.7, x_{IP} < 0.035, beta 1.5 GeV and |\eta(D*+/-)| < 1.5. The measured cross sections are compared to theoretical predictions. The results are presented in terms of the open-charm contribution to the diffractive proton structure function. The data demonstrate a strong sensitivity to the diffractive parton densities.Comment: 35 pages, 11 figures, 6 table

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

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

Virtue ethics and social psychology

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

Review of High Energy Diffraction in Real an Virtual Proton Scattering at HERA

The electron-proton collider HERA at DESY opened the door for the study of diffraction in real and virtual photon-proton scattering at center-of-mass energies W up to 250 GeV and for large negative mass squared -Q^2 of the virtual photon up to Q^2 = 1600 GeV^2. At W = 220 GeV and Q^2 = 4 GeV^2, diffraction accounts for about 15% of the total virtual photon proton cross section decreasing to ~5% at Q^2 = 200 GeV^2. An overview of the results obtained by the experiments H1 and ZEUS on the production of neutral vectormesons and on inclusive diffraction up to the year 2008 is presented.Comment: 124 pages, 114 figure

Combined Inclusive Diffractive Cross Sections Measured with Forward Proton Spectrometers in Deep Inelastic ep\it ep Scattering at HERA

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 √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 GeV 2 in photon virtuality, 0.00035 < xP < 0.09 in proton fractional momentum loss, 0.09 <{pipe}t{pipe}< 0.55 GeV 2 in squared four-momentum transfer at the proton vertex and 0.0018 < β <0.816 in β=x/xP, where x is the Bjorken scaling variable. © 2012 The Author(s).0H1 and ZEUS CollaborationsSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Events with an isolated lepton and missing transverse momentum and measurement of W production at HERA

A search for events containing an isolated electron or muon and missing transverse momentum produced in ep 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 PtX >25 GeV, a total of 23 events are observed compared to a prediction of 14.0 \pm 1.9. The total single W boson production cross section is measured as 1.06 \pm 0.16 (stat.) \pm 0.07 (sys) pb, in agreement with an SM expectation of 1.26 \pm 0.19 pb.Comment: 19 pages, 3 figures, v2 updated to correspond to Journal versio