4,102 research outputs found
Goldilocks Supersymmetry: Simultaneous Solution to the Dark Matter and Flavor Problems of Supersymmetry
Neutralino dark matter is well motivated, but also suffers from two
shortcomings: it requires gravity-mediated supersymmetry breaking, which
generically violates flavor constraints, and its thermal relic density \Omega
is typically too large. We propose a simple solution to both problems:
neutralinos freezeout with \Omega ~10-100, but then decay to ~1 GeV gravitinos,
which are simultaneously light enough to satisfy flavor constraints and heavy
enough to be all of dark matter. This scenario is naturally realized in
high-scale gauge-mediation models, ameliorates small scale structure problems,
and implies that ``cosmologically excluded'' models may, in fact, be
cosmologically preferred.Comment: 4 pages; v2: references added; v3: published versio
Minimal Supergravity with m_0^2 < 0
We extend the parameter space of minimal supergravity to negative values of
m_0^2, the universal scalar mass parameter defined at the grand unified scale.
After evolving to the weak scale, all scalars can be non-tachyonic with masses
consistent with collider constraints. This region of parameter space is
typically considered excluded by searches for charged dark matter, since the
lightest standard model superpartner is a charged slepton. However, if the
gravitino is the lightest supersymmetric particle, the charged slepton decays,
and this region is allowed. This region provides qualitatively new
possibilities for minimal supergravity, including spectra with light sleptons
and very heavy squarks, and models in which the lightest slepton is the
selectron. We show that the m_0^2 < 0 region is consistent with low energy
precision data and discuss its implications for particle colliders. These
models may provide signals of supersymmetry in even the first year of operation
at the Large Hadron Collider.Comment: 16 page
SuperWIMP Cosmology and Collider Physics
Dark matter may be composed of superWIMPs, superweakly-interacting massive
particles produced in the late decays of other particles. We focus here on the
well-motivated supersymmetric example of gravitino LSPs. Gravitino superWIMPs
share several virtues with the well-known case of neutralino dark matter: they
are present in the same supersymmetric frameworks (supergravity with R-parity
conservation) and naturally have the desired relic density. In contrast to
neutralinos, however, gravitino superWIMPs are impossible to detect by
conventional dark matter searches, may explain an existing discrepancy in Big
Bang nucleosynthesis, predict observable distortions in the cosmic microwave
background, and imply spectacular signals at future particle colliders.Comment: 12 pages, to appear in the proceedings of SUSY2004, the 12th
International Conference on Supersymmetry and Unification of Fundamental
Interactions, Tsukuba, Japan, 17-23 June 200
Leadership in higher education--its evolution and potential: A unique role facing critical challenges
Leadership is a key ingredient in the ultimate success or failure of any organization. In this article the authors review the research on leadership in general and then focus on how leadership in the academic world is similar to, yet distinct from, leadership in the private sector. Included in this discussion are a description of how leadership in colleges and universities has evolved, the characteristics that are unique to higher education together with their implications for effective leadership, and consideration of the immense challenges academic leaders face as they attempt to keep higher education responsive to the needs of business and industry. The authors also address the emergence of student affairs administration and the current crisis in academic leadership
Collider Signatures of SuperWIMP Warm Dark Matter
SuperWeakly-Interacting Massive Particles (superWIMPs) produced in the late
decays of other particles are well-motivated dark matter candidates and may be
favored over standard Weakly-Interacting Massive Particles (WIMPs) by small
scale structure observations. Among the most promising frameworks that
incorporate superWIMPs are R-parity conserving supersymmetry models in which
the lightest supersymmetric particle (LSP) is the gravitino or the axino. In
these well-defined particle models, astrophysical observations have direct
implications for possible measurements at future colliders.Comment: Contributed to the 2005 International Linear Collider Physics and
Detector Workshop and 2nd ILC Accelerator Workshop, Snowmass, Colorado, 14-27
Aug 2005. 3 pages, LaTeX, 1 figur
10 steps to a digital practice in the cloud : new levels of CPA firm workflow efficiency
https://egrove.olemiss.edu/aicpa_guides/2718/thumbnail.jp
Toward a Model for Fisheries Social Impact Assessment
This paper presents a model for Fisheries Social Impact Assessment (SIA) that lays the groundwork for development
of fisheries-focused, quantitative social assessments with a clear conceptual model. The usefulness of current fisheries SIA’s has been called into question by some
as incompatible with approaches taken by fisheries biologists and economists when assessing potential effects of management actions. Our model’s approach is closer to the economists’ and biologists’ assessments and is therefore more useful for Fishery Management Council members. The paper was developed by anthropologists initially brought together in 2004 for an SIA Modeling
Workshop by the National Marine Fisheries Service, NOAA. Opinions and conclusions expressed or implied are solely
those of the authors and do not necessarily reflect the views or policy of the National Marine Fisheries Service, NOAA
High performance in healthcare priority setting and resource allocation: a literature- and case study-based framework in the Canadian context
The Changing Demand for Culture: Estimation of Cultural Elasticities
Much past research on the nature of demand for recreation or cultural activities has been either economic models based on unrealistic assumptions about willingness-to-pay or sociological models that fail to provide an in-depth analysis of the forces actually affecting the decision to participate. This paper presents an attempt to combine some of the strengths of the traditional economic and sociological methods, while avoiding some of their weaknesses. The method developed produces an index called a cultural elasticity that quantitatively indicates how rates of participation maw be expected to change when certain economic and sociological characteristics in the population change. A numerical example is provided using a recent Canadian national survey on performing arts audiences. Strengths and limitations in the approach are also identified
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