R-parity Conservation via the Stueckelberg Mechanism: LHC and Dark Matter Signals

We investigate the connection between the conservation of R-parity in supersymmetry and the Stueckelberg mechanism for the mass generation of the B-L vector gauge boson. It is shown that with universal boundary conditions for soft terms of sfermions in each family at the high scale and with the Stueckelberg mechanism for generating mass for the B-L gauge boson present in the theory, electric charge conservation guarantees the conservation of R-parity in the minimal B-L extended supersymmetric standard model. We also discuss non-minimal extensions. This includes extensions where the gauge symmetries arise with an additional U(1)_{B-L} x U(1)_X, where U(1)_X is a hidden sector gauge group. In this case the presence of the additional U(1)_X allows for a Z' gauge boson mass with B-L interactions to lie in the sub-TeV region overcoming the multi-TeV LEP constraints. The possible tests of the models at colliders and in dark matter experiments are analyzed including signals of a low mass Z' resonance and the production of spin zero bosons and their decays into two photons. In this model two types of dark matter candidates emerge which are Majorana and Dirac particles. Predictions are made for a possible simultaneous observation of new physics events in dark matter experiments and at the LHC.Comment: 38 pages, 7 fig

Probing EWSB Naturalness in Unified SUSY Models with Dark Matter

We have studied Electroweak Symmetry Breaking (EWSB) fine-tuning in the context of two unified Supersymmetry scenarios: the Constrained Minimal Supersymmetric Model (CMSSM) and models with Non-Universal Higgs Masses (NUHM), in light of current and upcoming direct detection dark matter experiments. We consider both those models that satisfy a one-sided bound on the relic density of neutralinos, $\Omega_{\chi} h^2 < 0.12$, and also the subset that satisfy the two-sided bound in which the relic density is within the 2 sigma best fit of WMAP7 + BAO + H0 data. We find that current direct detection searches for dark matter probe the least fine-tuned regions of parameter-space, or equivalently those of lowest Higgs mass parameter $\mu$, and will tend to probe progressively more and more fine-tuned models, though the trend is more pronounced in the CMSSM than in the NUHM. Additionally, we examine several subsets of model points, categorized by common mass hierarchies; M_{\chi_0} \sim M_{\chi^\pm}, M_{\chi_0} \sim M_{\stau}, M_{\chi_0} \sim M_{\stop_1}, the light and heavy Higgs poles, and any additional models classified as "other"; the relevance of these mass hierarchies is their connection to the preferred neutralino annihilation channel that determines the relic abundance. For each of these subsets of models we investigated the degree of fine-tuning and discoverability in current and next generation direct detection experiments.Comment: 26 pages, 10 figures. v2: references added. v3: matches published versio

The Cosmology of Composite Inelastic Dark Matter

Composite dark matter is a natural setting for implementing inelastic dark matter - the O(100 keV) mass splitting arises from spin-spin interactions of constituent fermions. In models where the constituents are charged under an axial U(1) gauge symmetry that also couples to the Standard Model quarks, dark matter scatters inelastically off Standard Model nuclei and can explain the DAMA/LIBRA annual modulation signal. This article describes the early Universe cosmology of a minimal implementation of a composite inelastic dark matter model where the dark matter is a meson composed of a light and a heavy quark. The synthesis of the constituent quarks into dark mesons and baryons results in several qualitatively different configurations of the resulting dark matter hadrons depending on the relative mass scales in the system.Comment: 31 pages, 4 figures; references added, typos correcte

Evolution in the Cluster Early-type Galaxy Size-Surface Brightness Relation at z =~ 1

We investigate the evolution in the distribution of surface brightness, as a function of size, for elliptical and S0 galaxies in the two clusters RDCS J1252.9-2927, z=1.237 and RX J0152.7-1357, z=0.837. We use multi-color imaging with the Advanced Camera for Surveys on the Hubble Space Telescope to determine these sizes and surface brightnesses. Using three different estimates of the surface brightnesses, we find that we reliably estimate the surface brightness for the galaxies in our sample with a scatter of < 0.2 mag and with systematic shifts of \lesssim 0.05 mag. We construct samples of galaxies with early-type morphologies in both clusters. For each cluster, we use a magnitude limit in a band which closely corresponds to the rest-frame B, to magnitude limit of M_B = -18.8 at z=0, and select only those galaxies within the color-magnitude sequence of the cluster or by using our spectroscopic redshifts. We measure evolution in the rest-frame B surface brightness, and find -1.41 \+/- 0.14 mag from the Coma cluster of galaxies for RDCS J1252.9-2927 and -0.90 \+/- 0.12 mag of evolution for RX J0152.7-1357, or an average evolution of (-1.13 \+/- 0.15) z mag. Our statistical errors are dominated by the observed scatter in the size-surface brightness relation, sigma = 0.42 \+/- 0.05 mag for RX J0152.7-1357 and sigma = 0.76 \+/- 0.10 mag for RDCS J1252.9-2927. We find no statistically significant evolution in this scatter, though an increase in the scatter could be expected. Overall, the pace of luminosity evolution we measure agrees with that of the Fundamental Plane of early-type galaxies, implying that the majority of massive early-type galaxies observed at z =~ 1 formed at high redshifts.Comment: Accepted in ApJ, 16 pages in emulateapj format with 15 eps figures, 6 in colo

Constraints on supersymmetry with light third family from LHC data

We present a re-interpretation of the recent ATLAS limits on supersymmetry in channels with jets (with and without b-tags) and missing energy, in the context of light third family squarks, while the first two squark families are inaccessible at the 7 TeV run of the Large Hadron Collider (LHC). In contrast to interpretations in terms of the high-scale based constrained minimal supersymmetric standard model (CMSSM), we primarily use the low-scale parametrisation of the phenomenological MSSM (pMSSM), and translate the limits in terms of physical masses of the third family squarks. Side by side, we also investigate the limits in terms of high-scale scalar non-universality, both with and without low-mass sleptons. Our conclusion is that the limits based on 0-lepton channels are not altered by the mass-scale of sleptons, and can be considered more or less model-independent.Comment: 20 pages, 8 figures, 2 tables. Version published in JHE

Media coverage of climate change: an international comparison

We present an international comparison of broadsheet newspaper coverage of climate change. We employ two complementary theoretical lenses, multiple streams theory and institutional theory, to explore why climate change has become headline news in some countries but has received comparatively little coverage in others. The study utilises a worldwide sample across 41 different countries for the year 2008, covering 113 leading national broadsheet newspapers. A cross-sectional regression model is used to identify whether and how a range of contextual factors impact coverage of climate change. To a certain extent, a country’s direct exposure to climate change and the measures that have been taken to combat global warming influence the position of climate change on the media agenda. Crucially, however, we identify a number of contextual factors that impact climate change-related media coverage in different national contexts. In particular, we find a significantly positive relationship between regulatory quality and levels of media coverage. At the same time, unemployment trends are significantly negatively related to media attention to climate change. Gross domestic product per capita does not help to explain levels of climate change-related media coverage. In other words, climate change appears to have moved beyond simply being a ‘rich country issue’

A framework and a measurement instrument for sustainability of work practices in long-term care

<p>Abstract</p> <p>Background</p> <p>In health care, many organizations are working on quality improvement and/or innovation of their care practices. Although the effectiveness of improvement processes has been studied extensively, little attention has been given to sustainability of the changed work practices after implementation. The objective of this study is to develop a theoretical framework and measurement instrument for sustainability. To this end sustainability is conceptualized with two dimensions: routinization and institutionalization.</p> <p>Methods</p> <p>The exploratory methodological design consisted of three phases: a) framework development; b) instrument development; and c) field testing in former improvement teams in a quality improvement program for health care (N _teams= 63, N _individual= 112). Data were collected not until at least one year had passed after implementation.</p> <p>Underlying constructs and their interrelations were explored using Structural Equation Modeling and Principal Component Analyses. Internal consistency was computed with Cronbach's alpha coefficient. A long and a short version of the instrument are proposed.</p> <p>Results</p> <p>The χ²- difference test of the -2 Log Likelihood estimates demonstrated that the hierarchical two factor model with routinization and institutionalization as separate constructs showed a better fit than the one factor model (p < .01). Secondly, construct validity of the instrument was strong as indicated by the high factor loadings of the items. Finally, the internal consistency of the subscales was good.</p> <p>Conclusions</p> <p>The theoretical framework offers a valuable starting point for the analysis of sustainability on the level of actual changed work practices. Even though the two dimensions routinization and institutionalization are related, they are clearly distinguishable and each has distinct value in the discussion of sustainability. Finally, the subscales conformed to psychometric properties defined in literature. The instrument can be used in the evaluation of improvement projects.</p

The Triumph and Tragedy of Tobacco Control: A Tale of Nine Nations

The use of law and policy to limit tobacco consumption illustrates one of the greatest triumphs of public health in the late twentieth and early twenty-first centuries, as well as one of its most fundamental failures. Overall decreases in tobacco consumption throughout the developed world represent millions of saved lives and unquantifiable suffering averted. Yet those benefits have not been equally distributed. The poor and the undereducated have enjoyed fewer of the gains. In this review, we build on existing tobacco control scholarship and expand it both conceptually and comparatively. Our focus is the social gradient of smoking both within and across borders and how policy makers have been most effective in limiting smoking prevalence among the more privileged segments of society. To illustrate that point, we reference a range of literature on tobacco taxation, advertising, and public smoking in five economically advanced democracies—France, Germany, Japan, the United Kingdom, and the United States—and four less developed nations—India, China, Brazil, and South Africa—that together comprise 40% of the world’s population

Vitamin D in the general population of young adults with autism in the Faroe Islands

Vitamin D deficiency has been proposed as a possible risk factor for developing autism spectrum disorder (ASD). 25-Hydroxyvitamin D3 (25(OH)D3) levels were examined in a cross-sectional population-based study in the Faroe Islands. The case group consisting of a total population cohort of 40 individuals with ASD (aged 15–24 years) had significantly lower 25(OH)D3 than their 62 typically-developing siblings and their 77 parents, and also significantly lower than 40 healthy age and gender matched comparisons. There was a trend for males having lower 25(OH)D3 than females. Effects of age, month/season of birth, IQ, various subcategories of ASD and Autism Diagnostic Observation Schedule score were also investigated, however, no association was found. The very low 25(OH)D3 in the ASD group suggests some underlying pathogenic mechanism