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

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

Right-handed Neutrinos and R(D(∗))R(D^{(*)})

We explore scenarios where the $R(D^{(*)})$ anomalies arise from semitauonic decays to a right-handed sterile neutrino. We perform an EFT study of all five simplified models capable of generating at tree-level the lowest dimension electroweak operators that give rise to this decay. We analyze their compatibility with current $R(D^{(*)})$ data and other relevant hadronic branching ratios, and show that one simplified model is excluded by this analysis. The remainder are compatible with collider constraints on the mediator semileptonic branching ratios, provided the mediator mass is of order TeV. We also discuss the phenomenology of the sterile neutrino itself, which includes possibilities for displaced decays at colliders and direct searches, measurable dark radiation, and gamma ray signals.Comment: 30 pages, 13 figures. Updated collider constraints and discussions. Matches published version in JHE