14,962 research outputs found
Update on the Pyramid Scheme
We summarize recent work in which we attempt to make a consistent model of
LHC physics, from the Pyramid Scheme. The models share much with the NMSSM, in
particular, enhanced tree level contributions to the Higgs mass and a
preference for small tan {\beta}. There are 3 different singlet fields, and a
new strongly coupled gauge theory, so the constraints of perturbative
unification are quite different. We outline our general approach to the model,
which contains a Kahler potential for three of the low energy fields, which is
hard to calculate. Detailed calculations, based on approximations to the Kahler
potential, will be presented in a future publication.Comment: LaTeX 2e/ 9 page
UK household portfolios
This paper presents a detailed analysis of the composition of household portfolios, usingboth aggregate and micro-data. Among the key findings are that:• Most household wealth is held in the form of housing and pensions. Over time, there hasbeen a shift away from housing towards financial assets, driven largely by the growth inlife and pension funds.• Liquid financial wealth (excluding life and pension funds) is not predominantly held inrisky form. By far the most commonly held asset is an interest-bearing account at a bankor building society account. Of people with positive (liquid) financial wealth, more thanhalf is held in savings accounts.• The importance of risky assets in an individual’s portfolio varies according to theircharacteristics. The unconditional portfolio share held in risky assets (i.e. averagedacross those with and without any risky assets) rises with both age and total financialwealth. However, most of the variation in unconditional portfolio shares is due todifferences in ownership rates as opposed to the proportion of the portfolio held in riskyassets. Looking only at the people within each wealth decile who have risky assets, theconditional portfolio share is relatively constant across wealth, suggesting a possible rolefor entry costs or other fixed costs in explaining portfolio holdings. Multivariate analysisshows that the conditional portfolio share in risky assets actually falls with age asclassical portfolio theory would predict.• Finally, the tax treatment of savings products has an effect on portfolio choice. Separateprobit regressions for the ownership of tax-favoured assets and similar assets without thetax exemption, show that, controlling for other factors, marginal tax rates are important in determining asset ownership. These results are in accordance with those found by Poterba in the US
Apparatus for producing oxidation protection coatings for polymers
A polymeric substrate is coated with a metal oxide film to provide oxidation protection in low Earth orbital environments. The film contains about 4 volume percent polymer to provide flexibility. A coil of polymer materials moves through an ion beam as it is fed between reels. The ion beam first cleans the polymer material surface and then sputters the film material from a target onto this surface
Dynamical Systems On Three Manifolds Part II: 3-Manifolds,Heegaard Splittings and Three-Dimensional Systems
The global behaviour of nonlinear systems is extremely important in control
and systems theory since the usual local theories will only give information
about a system in some neighbourhood of an operating point. Away from that
point, the system may have totally different behaviour and so the theory
developed for the local system will be useless for the global one.
In this paper we shall consider the analytical and topological structure of
systems on 2- and 3- manifolds and show that it is possible to obtain systems
with 'arbitrarily strange' behaviour, i.e., arbitrary numbers of chaotic
regimes which are knotted and linked in arbitrary ways. We shall do this by
considering Heegaard Splittings of these manifolds and the resulting systems
defined on the boundaries.Comment: 15 pages with 9 pictures. Accepted by Int. J. of Bifurcation and
Chao
Surface texturing of fluoropolymers
A method is disclosed for improving surface texture for adhesive bonding, metal bonding, substrate plating, decal substrate preparation, and biomedical implant applications. The surface to be bonded is dusted in a controlled fashion to produce a disbursed layer of fine mesh particles which serve as masks. The surface texture is produced by impinging gas ions on the masked surface. The textured surface takes the form of pillars or cones. The bonding material, such as a liquid epoxy, flows between the pillars which results in a bond having increased strength. For bonding metals a thin film of metal is vapor or sputter deposited onto the textured surface. Electroplating or electroless plating is then used to increase the metal thickness in the desired amount
Deposition of diamondlike carbon films
A diamondlike carbon film is deposited in the surface of a substrate by exposing the surface to an argon ion beam containing a hydrocarbon. The current density in the ion beam is low during initial deposition of the film. Subsequent to this initial low current condition, the ion beam is increased to full power. At the same time, a second argon ion beam is directed toward the surface of the substrate. The second ion beam has an energy level much greater than that of the ion beam containing the hydrocarbon. This addition of energy to the system increases mobility of the condensing atoms and serves to remove lesser bound atoms
A Pyramid Scheme for Particle Physics
We introduce a new model, the Pyramid Scheme, of direct mediation of SUSY
breaking, which is compatible with the idea of Cosmological SUSY Breaking
(CSB). It uses the trinification scheme of grand unification and avoids
problems with Landau poles in standard model gauge couplings. It also avoids
problems, which have recently come to light, associated with rapid stellar
cooling due to emission of the pseudo Nambu-Goldstone Boson (PNGB) of
spontaneously broken hidden sector baryon number. With a certain pattern of
R-symmetry breaking masses, a pattern more or less required by CSB, the Pyramid
Scheme leads to a dark matter candidate that decays predominantly into leptons,
with cross sections compatible with a variety of recent observations. The dark
matter particle is not a thermal WIMP but a particle with new strong
interactions, produced in the late decay of some other scalar, perhaps the
superpartner of the QCD axion, with a reheat temperature in the TeV range. This
is compatible with a variety of scenarios for baryogenesis, including some
novel ones which exploit specific features of the Pyramid Scheme.Comment: JHEP Latex, 32 pages, 1 figur
Oxidation protection coatings for polymers
A polymeric substrate is coated with a metal oxide film to provide oxidation protection in low Earth orbital environments. The film contains about 4 volume percent polymer to provide flexibility. A coil of polymer material moves through an ion beam as it is fed between reels. The ion beam first cleans the polymer material surface and then sputters the film material from a target onto this surface
Supersymmetry, the Cosmological Constant and a Theory of Quantum Gravity in Our Universe
There are many theories of quantum gravity, depending on asymptotic boundary
conditions, and the amount of supersymmetry. The cosmological constant is one
of the fundamental parameters that characterize different theories. If it is
positive, supersymmetry must be broken. A heuristic calculation shows that a
cosmological constant of the observed size predicts superpartners in the TeV
range. This mechanism for SUSY breaking also puts important constraints on low
energy particle physics models. This essay was submitted to the Gravity
Research Foundation Competition and is based on a longer article, which will be
submitted in the near future
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