239,254 research outputs found

    Lower Limits on Soft Supersymmetry-Breaking Scalar Masses

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    Working in the context of the CMSSM, we argue that phenomenological constraints now require the universal soft supersymmetry-breaking scalar mass m_0 be non-zero at the input GUT scale. This conclusion is primarily imposed by the LEP lower limit on the Higgs mass and the requirement that the lightest supersymmetric particle not be charged. We find that m_0 > 0 for all tan beta if mu 0 only when tan beta sim 8 and one allows an uncertainty of 3+ GeV in the theoretical calculation of the Higgs mass. Upper limits on flavour-changing neutral interactions in the MSSM squark sector allow substantial violations of non-universality in the m_0 values, even if their magnitudes are comparable to the lower limit we find in the CMSSM. Also, we show that our lower limit on m_0 at the GUT scale in the CMSSM is compatible with the no-scale boundary condition m_0 = 0 at the Planck scale.Comment: 11 pages, latex, 6 eps figure

    Astroparticle Aspects of Supersymmetry

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    After recalling the motivations for expecting supersymmetry to appear at energies below 1 TeV, the reasons why the lightest supersymmetric particle is an ideal candidate for cold dark matter are reviewed from a historical perspective. Recent calculations of the relic density including coannihilations and rapid annihilations through direct-channel Higgs boson poles are presented. The experimental constraints from LEP and elsewhere on supersymmetric dark matter are reviewed, and the prospects for its indirect or direct detection are mentioned. The potential implications of a Higgs boson weighing about 115 GeV and the recent measurement of the anomalous magnetic moment of the muon are summarized.Comment: 12 pages, 10 eps figures, invited plenary talk at conference on 30 Years Of Supersymmetry, Oct. 2000, Minneapolis, Minnesot

    Quantum effects from a purely geometrical relativity theory

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    A purely geometrical relativity theory results from a construction that produces from three-dimensional space a happy unification of Kaluza's five-dimensional theory and Weyl's conformal theory. The theory can provide geometrical explanations for the following observed phenomena, among others: (a) lifetimes of elementary particles of lengths inversely proportional to their rest masses; (b) the equality of charge magnitude among all charged particles interacting at an event; (c) the propensity of electrons in atoms to be seen in discretely spaced orbits; and (d) `quantum jumps' between those orbits. This suggests the possibility that the theory can provide a deterministic underpinning of quantum mechanics like that provided to thermodynamics by the molecular theory of gases.Comment: 7 pages, LaTeX jpconf.cls (Institute of Physics Publishing), 6 Encapsulated PostScript figures (Fig. 6 is 1.8M uncompressed); Presented at VI Mexican School on Gravitation and Mathematical Physics "Approaches to Quantum Gravity

    Understanding Small Business Networking and ICTs: Exploring Face-to-Face and ICT-related opportunity creation mediated by Social Capital in East of England Micro-businesses

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    Small businesses that are sole traders or micro-businesses—with few, if any employees notoriously suffer from a ‘liability of smallness’ (Aldrich and Auster 1986), including poor access to various resources. However, many authors argue that the inherent problems of smallness can be overcome with networking and good network connections. Resources, the opportunities to access them and other benefits apparent from networks and networking are readily apparent in the literature. However, few articles, if any, have examined small business networking from the perspective of this study—using in-depth qualitative methods, the theoretical construct of social capital and exploring the increasing role of Information and Communication Technologies (ICTs) in networks and networking—as part of understanding a variety of entrepreneurial opportunities. This article provides much needed empirical insights on how and if ICTs support opportunity creation amongst small businesses within a spatial and social network perspective. Its ‘media ecology’ approach does not over-prioritise the role of ICTs, but instead examines their interrelationships with face-to-face contact—putting technology in its ‘place’. The article focuses on the notion of ‘opportunity creation’ from networks, since this is the outcome critical for the small businesses themselves in order to generate economic benefits for their business. It seeks to provide a higher level, outcomebased framework that helps specify the various sorts of opportunities created by networks for small businesses, based on original ethnographic material and findings from a case study of East of England micro-businesses

    Seeking Out Difference, Searching New Markets, Hunting the Bargain: Globalized Consumption and Collecting in an eBay Era

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    The Abduction

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    From HERA to the LHC

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    Some personal comments are given on some of the exciting interfaces between the physics of HERA and the LHC. These include the quantitative understanding of perturbative QCD, the possible emergence of saturation phenomena and the Colour-Glass Condensate at small x and large Q^2, the link between forward physics and ultra-high-energy cosmic rays, and new LHC opportunities opened up by the discovery of rapidity-gap events at HERA, including the search for new physics such as Higgs bosons in double-diffraction events.Comment: 14 pages and 9 figures latex using cernrep.cls and mcite.sty, Individual Contribution to the HERA-LHC Worksho
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