1,026 research outputs found

    The Delphi method: methodological issues arising from a study examining factors influencing the publication or non-publication of mental health nursing research

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    Purpose – The paper describes how the classic Delphi method can be adapted and structured to ensure that specific research questions are clearly addressed. Design/methodology/approach – As part of a larger mixed method project, a modified Delphi study was undertaken to explore factors influencing publication and non-publication of mental health nursing research. Findings - This paper reports brief findings from the Delphi study. However, its main focus is the methodological issues arising from the Delphi method. Implications - The paper argues that the classic Delphi method can be adapted and structured to ensure that specific research questions are able to be clearly answered. The adaptations are pragmatic in approach and in keeping with the general principles underpinning the Delphi method, while successfully addressing the problems of attrition and previous criticism of homogenous panels. Originality/value - This paper offers some practical solutions to issue arising from undertaking research using the Delphi method

    Decays of Scalar and Pseudoscalar Higgs Bosons into Fermions: Two-loop QCD Corrections to the Higgs-Quark-Antiquark Amplitude

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    As a first step in the aim of arriving at a differential description of neutral Higgs boson decays into heavy quarks, hQQˉXh \to Q {\bar Q}X, to second order in the QCD coupling αS\alpha_S, we have computed the hQQˉhQ{\bar Q} amplitude at the two-loop level in QCD for a general neutral Higgs boson which has both scalar and pseudoscalar couplings to quarks. This amplitude is given in terms of a scalar and a pseudoscalar vertex form factor, for which we present closed analytic expressions in terms of one-dimensional harmonic polylogarithms of maximum weight 4. The results hold for arbitrary four-momentum squared, q2q^2, of the Higgs boson and of the heavy quark mass, mm. Moreover we derive the approximate expressions of these form factors near threshold and in the asymptotic regime m2/q21m^2/q^2 \ll 1.Comment: 56 pages, 2 figure

    Looking through drumlins: testing the application of ground penetrating radar

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    ACKNOWLEDGEMENTS We thank the editor, Bernd Kulessa, for his review and support, and John Hiemstra and an anonymous reviewer for helpful comments and suggestions. This work was supported by an equipment loan from the UK Natural Environment Research Council (NERC) Geophysical Equipment Facility (Loan 990) and a University of Aberdeen, College of Physical Sciences’ Research and Teaching Enhancement Fund. All authors are indebted to the NERC Geophysical Equipment Facility staff for training in the use of the antennas and GPS. J.C.E. thanks the Denisons for funding his PhD. We also thank Wharton Hall and Shaw Paddock farms for access to the field sites.Peer reviewedPublisher PD

    From arbitrariness to ambiguities in the evaluation of perturbative physical amplitudes and their symmetry relations

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    A very general calculational strategy is applied to the evaluation of the divergent physical amplitudes which are typical of perturbative calculations. With this approach in the final results all the intrinsic arbitrariness of the calculations due to the divergent character is still present. We show that by using the symmetry properties as a guide to search for the (compulsory) choices in such a way as to avoid ambiguities, a deep and clear understanding of the role of regularization methods emerges. Requiring then an universal point of view for the problem, as allowed by our approach, very interesting conclusions can be stated about the possible justifications of most intriguing aspect of the perturbative calculations in quantum field theory: the triangle anomalies.Comment: 16 pages, no figure

    Two-Loop Bhabha Scattering in QED

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    In the context of pure QED, we obtain analytic expressions for the contributions to the Bhabha scattering differential cross section at order alpha^4 which originate from the interference of two-loop photonic vertices with tree-level diagrams and from the interference of one-loop photonic diagrams amongst themselves. The ultraviolet renormalization is carried out. The IR-divergent soft-photon emission corrections are evaluated and added to the virtual cross section. The cross section obtained in this manner is valid for on-shell electrons and positrons of finite mass, and for arbitrary values of the center of mass energy and momentum transfer. We provide the expansion of our results in powers of the electron mass, and we compare them with the corresponding expansion of the complete order alpha^4 photonic cross section, recently obtained in hep-ph/0501120. As a by-product, we obtain the contribution to the Bhabha scattering differential cross section of the interference of the two-loop photonic boxes with the tree-level diagrams, up to terms suppressed by positive powers of the electron mass. We evaluate numerically the various contributions to the cross section, paying particular attention to the comparison between exact and expanded results.Comment: 35 pages, 18 figure

    Lorentz and CPT symmetries in commutative and noncommutative spacetime

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    We investigate the fermionic sector of a given theory, in which massive and charged Dirac fermions interact with an Abelian gauge field, including a non standard contribution that violates both Lorentz and CPT symmetries. We offer an explicit calculation in which the radiative corrections due to the fermions seem to generate a Chern-Simons-like effective action. Our results are obtained under the general guidance of dimensional regularization, and they show that there is no room for Lorentz and CPT violation in both commutative and noncommutative spacetime.Comment: RevTex4, 7 pages, to be published in J. Phys.

    Withdrawn, strong, kind, but de-gendered: Non-disabled South Africans’ stereotypes concerning persons with physical disabilities

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    The present paper examines stereotyping in relation to physical disability and gender in the South Africa. Cross-sectional data for the present study were gathered using free response items in a large survey (n = 1990) examining the attitudes of people without disability towards different facetsof sexuality and disability. The most prominent stereotypes found in thepresent study were those which characterised PWPD as withdrawn and shy, SuperCrips, or happy, funny, and kind. The findings in the present papersuggest that stereotypes of PWPD are not overwhelmingly de-sexualising, but are undifferentiated by gender

    Renormalization of the Inverse Square Potential

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    The quantum-mechanical D-dimensional inverse square potential is analyzed using field-theoretic renormalization techniques. A solution is presented for both the bound-state and scattering sectors of the theory using cutoff and dimensional regularization. In the renormalized version of the theory, there is a strong-coupling regime where quantum-mechanical breaking of scale symmetry takes place through dimensional transmutation, with the creation of a single bound state and of an energy-dependent s-wave scattering matrix element.Comment: 5 page
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