239,254 research outputs found
Lower Limits on Soft Supersymmetry-Breaking Scalar Masses
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
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
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
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
From HERA to the LHC
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
Report drawn up on behalf of the Committee on Energy and Research on the first periodical report from the Commission of the European Communities to the Council on the Community action programme for the rational use of energy and draft recommendations of the Council. EP Working Documents, document 314/76, 30 September 1976
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