A 130 GeV Gamma Ray Signal from Supersymmetry

The viability of neutralino dark matter as an explanation of the 130 GeV gamma ray signal from the Galactic Center recently observed by the Fermi Large Area Telescope is examined. It is found that the signal can be compatible with a sharp feature from internal bremsstrahlung from a mostly bino dark matter particle of mass around 145 GeV, augmented by a contribution from annihilation into gamma+Z via a small wino admixture. This scenario circumvents the problematic overproduction of lower energy continuum photons that plague line interpretations of this signal. Sleptons approximately degenerate in mass with the neutralino are required to enhance the internal bremsstrahlung feature.Comment: 16 pages, 2 figures. Fit to Fermi data updated to include data for the full spectrum where possible. Main results and conclusions unchange

The Status of Neutralino Dark Matter

The lightest neutralino in supersymmetry is the most studied dark matter candidate. This writeup reviews the status of neutralino dark matter in minimal and nonminimal supersymmetric models in light of recent null results at the XENON100 experiment and the observation of a 130 GeV gamma ray signal from the Galactic Center by the Fermi LAT.Comment: Contribution to the proceedings of the CETUP* 2013 Dark Matter Program, Lead/Deadwood, South Dakot

Competitiveness assessment of tourism in Sierra Leone : a cluster-based approach

Seven years out of brutal conflict, Sierra Leone is now a peaceful and stable country. Yet, its strides toward economic recovery and competitiveness have been modest even in sectors such as tourism, which used to be a major generator of foreign exchange revenues prior to the conflict. This paper presents a cluster-based analysis of the tourism sector in Sierra Leone. The analysis shows that tourism in Sierra Leone draws entirely on basic factor conditions such as natural endowments; high-end lodging, catering, and entertainment services are virtually nonexistent. The cluster mapping exercise reveals that several non-profit organizations are present and active within the Sierra Leone tourism cluster but that the role of commercial enterprises has been somewhat limited. A critical mass of basic service providers has emerged over time, but their functions are often hindered by the absence of a market-based incentive regime and weaknesses in backbone infrastructure services. There is a mismatch of effort by the public and private sectors. An important policy implication arising from the analysis is for Sierra Leone to initiate a joint action among tourism entrepreneurs and policymakers to develop a coherent business strategy toward overcoming the bottlenecks of skill deficiency, policy ineffectiveness, and lack of infrastructure and market access.Cultural Policy,Transport Economics Policy&Planning,Cultural Heritage&Preservation,Tourism and Ecotourism,Accommodation&Tourism Industry

Comment on Calculation of Positron Flux from Galactic Dark Matter

Energetic positrons produced in annihilation or decay of dark matter particles in the Milky Way can serve as an important indirect signature of dark matter. Computing the positron flux expected in a given dark matter model involves solving transport equations, which account for interaction of positrons with matter and galactic magnetic fields. Existing calculations solve the equations inside the diffusion zone, where galactic magnetic fields confine positrons, and assume vanishing positron density on the boundaries of this zone. However, in many models, a substantial fraction of the dark matter halo lies outside the diffusion zone. Positrons produced there can then enter the diffusion zone and get trapped, potentially reaching the Earth and increasing the expected flux. We calculate this enhancement for a variety of models. We also evaluate the expected enhancement of the flux of energetic photons produced by the inverse Compton scattering of the extra positrons on starlight and cosmic microwave background. We find maximal flux enhancements of order 20% in both cases.Comment: 18 pages, 6 figures. Final version accepted for publication in Physical Review

Transforming an Unsustainable Project into Sustainable Rural Financial Institutions: The Case of the Small Farmer Co-operatives Ltd. (SFCLs) in Nepal

Over the last decade, Nepal has turned into a microfinance laboratory, exploring various approaches to provide financial services to the rural poor, both in the hill and plain areas of the country. The list of institutions and programs engaged in rural finance is long and includes informal credit and savings associations, savings and credit co-operatives, multi service cooperatives, Grameen Banks, village banks, government and privately owned development banks as well as microfinance NGOs. Rural Finance Nepal (RUFIN) is a joint Nepali-German project, implemented by the Agricultural Development Bank of Nepal (ADBN), with technical assistance from the German Agency for Technical Co-operation (GTZ). RUFIN aims at bringing sustainable financial services to the rural poor. The largest provider of rural credit is the Agricultural Development Bank of Nepal (ADBN). In 1975 it started the Small Farmer Development Program (SFDP), the ?mother? of all microfinance activities in Nepal, by introducing the joint liability concept to the country. IFAD was the first major donor, followed by Asian Development Bank. For a long time, the SFDP was considered an unsustainable credit program with low recovery rates and high overhead costs. Responding to this challenge, the ADBN started in the early 90?s to transfer this program into autonomous and member-owned financial institutions, as part of its overall reform program. This paper, through a comprehensive financial analysis, reviews the financial sustainability of these co-operative microfinance institutions, which are known in Nepal as Small Farmer Co-operatives Ltd. (SFCLs). The results of this viability check are very encouraging, and demonstrate that profitable microfinance business and outreach to the poor are not merely fantasy, but can be reality. --

Antiprotons from Dark Matter: Effects of a Position-Dependent Diffusion Coefficient

Energetic antiprotons in cosmic rays can serve as an important indirect signature of dark matter. Conventionally, the antiproton flux from dark matter decays or annihilations is calculated by solving the transport equation with a space-independent diffusion coefficient within the diffusion zone of the galaxy, and assuming free propagation outside this zone. Antiproton sources outside of the diffusion zone are ignored. In reality, it is far more likely that the diffusion coefficient increases smoothly with distance from the disk, and the outlying part of the dark matter halo ignored in the conventional approach can be significant, containing as much as 90% of the galactic dark matter by mass in some models. We extend the conventional approach to address these issues. We obtain analytic approximations and numerical solutions for antiproton flux assuming that the diffusion coefficient increases exponentially with the distance from the disk, and including contributions from dark matter annihilations/decays in essentially the full dark matter halo. We find that the antiproton flux predicted in this model deviates from the conventional calculation for the same dark matter parameters by up to about 25%.Comment: minor corrections and clarifications. main results and conclusions unchanged. final version accepted for publication in PR