723 research outputs found
Supersymmetry Breaking by Constant Boundary Superpotentials in Warped Space
Supersymmetry breaking by constant (field independent) superpotentials
localized at boundaries is studied in a supersymmetric warped space model. We
calculate the Kaluza-Klein mass spectrum of the hypermultiplet. We take into
account of the radion and the compensator supermultiplets, as well as the bulk
mass for the hypermultiplet. The mass splitting is similar to that of the
Scherk-Schwarz supersymmetry breaking (in flat space) for large , and has
an interesting dependence on the bulk mass parameter . We show that the
radius is stabilized by the presence of the constant boundary superpotentials.Comment: 24 pages, 9 figures; Section 5 is replaced by the new analysis of the
radius stabilization, small modifications mad
Infant feeding practice of HIV positive mothers and its determinants in selected health institutions of Addis Ababa, Ethiopia
Background: Avoidance of all breast-feeding by HIV infected mothers is recommended when replacement feeding is acceptable, feasible, affordable, sustainable, and safe. Whereas for women whose HIV status is unknown or negative, exclusive breastfeeding for the first six months is the single infant feeding option recommended. Objective: To assess the infant feeding practice of HIV positive mothers and its determinants.Methods: A cross sectional study with analytical component was conducted in 13 purposively selected health institutions with ART and PMTCT facilities in Addis Ababa during March, 2008. A total of 327 HIV positive motherswith their young infants visiting the respective health institutions were recruited in order of arrival, and assessed for their infant feeding practices.Results: Exclusive replacement feeding (ERF), exclusive breastfeeding (EBF) and mixed feeding (MF) were 46.8%, 30.6%, and 15.3% respectively. The predictors for choosing ERF were mode of delivery (
D-term Dynamical Supersymmetry Breaking Generating Split N=2 Gaugino Masses of Mixed Majorana-Dirac Type
Under a few mild assumptions, N=1 supersymmetry in four dimensions is shown
to be spontaneously broken in a self-consistent Hartree-Fock approximation of
BCS/NJL type to one-loop off-shell, in the gauge theory specified by the gauge
kinetic function and the superpotential of adjoint chiral superfields, in
particular, that possesses N=2 extended supersymmetry spontaneously broken to
N=1 at tree level. The N=2 gauginos receive mixed Majorana-Dirac masses and are
split. We derive an explicit form of the gap equation, showing the existence of
a nontrivial solution.Comment: 4 pages, the paper extended (a numerical plot of the solution to the
gap equation, an estimate of the decay rate of the metastable vacuum, and
discussion on nonvanishing term induced by the D term dynamical
supersymmetry breaking diven), references adde
Prejudice Reduction in Public Schools: A Dialogic Approach
Increasingly, students are facing hostility and violence as a result of one or more of their social group memberships. Such prejudicial attitudes and actions contribute to antagonistic intergroup relationships in public schools (i.e., K–12). This article examines dialogic approaches to prejudice reduction, with a specific emphasis on intergroup dialogue in public K–12 schools. Evidence-based steps and strategies that educators can use to develop intergroup dialogue competencies and cultivate a more dialogic environment in their schools and classrooms are also introduced
Radius stabilization by constant boundary superpotentials in warped space
A warped space model with a constant boundary superpotential has been an
efficient model both to break supersymmetry and to stabilize the radius, when
hypermultiplet, compensator and radion multiplet are taken into account. In
such a model of the radius stabilization, the radion and moduli masses, the
gravitino mass and the induced soft masses are studied. We find that a lighter
physical mode composed of the radion and the moduli can have mass of the order
of a TeV and that the gravitino mass can be of the order of 10 GeV. It is
also shown that soft mass induced by the anomaly mediation can be of the order
of 100GeV and can be dominant compared to that mediated by bulk fields.
Localized F terms and D terms are discussed as candidates of cancelling the
cosmological constant. We find that there is no flavor changing neutral current
problem in a wide range of parameters.Comment: 21 pages, small modifications made and references adde
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Education and Outreach for the International Polar Year
If the 65 educators, scientists, and media specialists who gathered at the "Bridging the Poles" workshop in Washington, D.C. last June have their way a semitrailer truck labeled "Got Snow?" would traverse the country during the International Polar Year (IPY) of 2007-2009 loaded with polar gear, interactive activities, and a snowmaker. We would significantly increase the number of Arctic residents—especially indigenous Alaskans—with Ph.D.s. We would build exchange programs between inner city youths and polar residents. Polar exhibitions would open at natural history and art museums and zoos. And polar postage stamps, interactive polar computer games, national polar book-of-the-month recommendations, made-for-TV polar documentaries, and a polar youth forum would bring the poles front and center to the public's attention
New Form of the T-Duality Due to the Stability of a Compact Dimension
We study behaviors of a compact dimension and the -duality, in the
presence of the wrapped closed bosonic strings. When the closed strings
interact and form another system of strings, the radius of compactification
increases. This modifies the -duality, which we call it as -duality-like.
Some effects of the -duality-like will be studied.Comment: 12 pages, Latex, no figur
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Bridging the Poles: Education Linked with Research: A Report on the Workshop: 23-25 June 2004, Washington, D.C.
The goals of the "Bridging the Poles" workshop of June 23-25, 2004 were to define strategies to engage the next generation of polar scientists, engineers and leaders, and inspire and educate the general public. The timeframe considered was the next five years, including maximizing the educational impact of the International Polar Year (IPY) in 2007-2009 (see inset below). The ca. 65 participants included K-12 educators, undergraduate professors, Arctic and Antarctic research scientists, Alaskan natives and residents, museum curators, representatives from agencies, the media and international programs. The workshop focused on four major themes: Reaching different levels; Engaging diverse communities; Possibilities for thematic areas; and Programs to feature nationally and internationally. The 22 roundtable discussions on these topics resulted in numerous recommendations to engage both future scientists and the general public. This report synthesizes opportunities for polar education and outreach identified at the workshop, recommends ways to maximize the impact of the IPY, and proposes "Next Steps" to develop polar education and outreach over the next five years
Molten Salt Thermal Energy Storage Systems
The feasibility of storing thermal energy at temperatures of 450 C to 535 C in the form of latent heat of fusion was examined for over 30 inorganic salts and salt mixtures. Alkali carbonate mixtures were chosen as phase-change storage materials in this temperature range because of their relatively high storage capacity and thermal conductivity, moderate cost, low volumetric expansion upon melting, low corrosivity, and good chemical stability. Means of improving heat conduction through the solid salt were explored
(S)fermion Masses in Fat Brane Scenario
We discuss the fermion mass hierarchy and the flavor mixings in the fat brane
scenario of a five dimensional SUSY theory. Assuming that the matter fields
lives in the bulk, their zero mode wave functions are Gaussians, and Higgs
fields are localized on the brane, we find simple various types of the matter
configurations generating the mass matrices consistent with experimental data.
Sfermion mass spectrum is also discussed using the matter configurations found
above. Which type of squark mass spectra (the degeneracy, the decoupling and
the alignment) is realized depends on the relative locations of SUSY breaking
brane and the brane where Higgs fields are localized.Comment: 18 pages, LaTe
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