1,199 research outputs found

    Distance Measurement and Îș\kappa-Deformed Propagation of Light and Heavy Probes

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    We investigate the implications for the measurability of distances of a covariant dimensionful ``Îș\kappa'' deformation of D=4 relativistic symmetries, with quantum time coordinate and modified Heisenberg algebra. We show that the structure of the deformed mass-shell condition has significant implications for measurement procedures relying on light probes, whereas in the case of heavy probes the most sizeable effect is due to the nontrivial commutation relation between three-momenta and quantum time coordinate. We argue that these findings might indicate that Îș\kappa-Poincar\'e symmetries capture some aspects of the physics of the Quantum-Gravity vacuum.Comment: 13 pages, Latex, to appear in Int. J. Mod. Phys.

    Baryogenesis from baryon number violating scalar interactions

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    In the following work we consider the possibility of explaining the observed baryon number asymmetry in the universe from simple baryon number violating modifications, involving massive scalar bosons, to the Standard Model. In these cases baryon number violation is mediated through a combination of Yukawa and scalar self-coupling interactions. Starting with a previously compiled catalogue of baryon-number violating extensions of the Standard Model, we identify the minimal subsets which can induce a B−LB-L asymmetry and thus be immune to sphaleron washout. For each of these models, we identify the region of parameter space that leads to the production of a baryon number asymmetry of the correct order of magnitude.Comment: 14 pages, 3 Postscript figure

    Within-river phosphorus retention: accounting for a missing piece in the watershed phosphorus puzzle

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    The prevailing "puzzle" in watershed phosphorus (P) management is how to account for the nonconservative behavior (retention and remobilization) of P along the land-freshwater continuum. This often hinders our attempts to directly link watershed P sources with their water quality impacts. Here, we examine aspects of within-river retention of wastewater effluent P and its remobilization under high flows. Most source apportionment methods attribute P loads mobilized under high flows (including retained and remobilized effluent P) as nonpoint agricultural sources. We present a new simple empirical method which uses chloride as a conservative tracer of wastewater effluent, to quantify within-river retention of effluent P, and its contribution to river P loads, when remobilized under high flows. We demonstrate that within-river P retention can effectively mask the presence of effluent P inputs in the water quality record. Moreover, we highlight that by not accounting for the contributions of retained and remobilized effluent P to river storm-flow P loads, existing source apportionment methods may significantly overestimate nonpoint agricultural sources and underestimate wastewater sources in mixed land-use watersheds. This has important implications for developing effective watershed remediation strategies, where remediation needs to be equitably and accurately apportioned among point and nonpoint P contributors

    Effective action in DSR1 quantum field theory

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    We present the one-loop effective action of a quantum scalar field with DSR1 space-time symmetry as a sum over field modes. The effective action has real and imaginary parts and manifest charge conjugation asymmetry, which provides an alternative theoretical setting to the study of the particle-antiparticle asymmetry in nature.Comment: 8 page

    Change management: The case of the elite sport performance team

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    The effective and efficient implementation of change is often required for both successful performance and management survival across a host of contemporary domains. However, although of major theoretical and practical significance, research to date has overlooked the application of change management (hereafter CM) knowledge to the elite sport performance team environment. Considering that the success of ‘off-field’ sports businesses are largely dependent on the performances of their ‘on-field’ team, this article explores the application of current CM theorizing to this specific setting and the challenges facing its utility. Accordingly, we identify the need and importance of developing theory specific to this area, with practical application in both sport and business, through examination of current knowledge and identification of the domain's unique, dynamic and contested properties. Markers of successful change are then suggested to guide initial enquiry before the article concludes with proposed lines of research which may act to provide a valid and comprehensive theoretical account of CM to optimize the research and practice of those working in the field

    Culture change in elite sport performance teams: Examining and advancing effectiveness in the new era

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    Reflecting the importance of optimizing culture for elite teams, Fletcher and Arnold (2011) recently suggested the need for expertise in culture change. Acknowledging the dearth of literature on the specific process, however, the potential effectiveness of practitioners in this area is unknown. The present paper examines the activity's precise demands and the validity of understanding in sport psychology and organizational research to support its delivery. Recognizing that sport psychologists are being increasingly utilized by elite team management, initial evidence-based guidelines are presented. Finally, to stimulate the development of ecologically valid, practically meaningful knowledge, the paper identifies a number of future research directions
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