Central Exclusive Production in QCD

We investigate the theoretical description of the central exclusive production process, h1+h2 -> h1+X+h2. Taking Higgs production as an example, we sum logarithmically enhanced corrections appearing in the perturbation series to all orders in the strong coupling. Our results agree with those originally presented by Khoze, Martin and Ryskin except that the scale appearing in the Sudakov factor, mu=0.62 \sqrt{\hat{s}}, should be replaced with mu=\sqrt{\hat{s}}, where \sqrt{\hat{s}} is the invariant mass of the centrally produced system. We confirm this result using a fixed-order calculation and show that the replacement leads to approximately a factor 2 suppression in the cross-section for central system masses in the range 100-500 GeV.Comment: 41 pages, 19 figures; minor typos fixed; version published in JHE

The Spin Structure of the Nucleon

We present an overview of recent experimental and theoretical advances in our understanding of the spin structure of protons and neutrons.Comment: 84 pages, 29 figure

Environmental, Institutional, and Demographic Predictors of Environmental Literacy among Middle School Children

Building environmental literacy (EL) in children and adolescents is critical to meeting current and emerging environmental challenges worldwide. Although environmental education (EE) efforts have begun to address this need, empirical research holistically evaluating drivers of EL is critical. This study begins to fill this gap with an examination of school-wide EE programs among middle schools in North Carolina, including the use of published EE curricula and time outdoors while controlling for teacher education level and experience, student attributes (age, gender, and ethnicity), and school attributes (socio-economic status, student-teacher ratio, and locale). Our sample included an EE group selected from schools with registered school-wide EE programs, and a control group randomly selected from NC middle schools that were not registered as EE schools. Students were given an EL survey at the beginning and end of the spring 2012 semester. Use of published EE curricula, time outdoors, and having teachers with advanced degrees and mid-level teaching experience (between 3 and 5 years) were positively related with EL whereas minority status (Hispanic and black) was negatively related with EL. Results suggest that school-wide EE programs were not associated with improved EL, but the use of published EE curricula paired with time outdoors represents a strategy that may improve all key components of student EL. Further, investments in teacher development and efforts to maintain enthusiasm for EE among teachers with more than 5 years of experience may help to boost student EL levels. Middle school represents a pivotal time for influencing EL, as improvement was slower among older students. Differences in EL levels based on gender suggest boys and girls may possess complementary skills sets when approaching environmental issues. Our findings suggest ethnicity related disparities in EL levels may be mitigated by time spent in nature, especially among black and Hispanic students

Temporal pessimism and spatial optimism in environmental assessments: An 18-nation study

The personal assessments of the Current and expected future state of the environment by 3232 community respondents in 18 nations were investigated at the local, national, and global spatial levels. These assessments were compared to a ranking of each country's environmental quality by air expert panel. Temporal pessimism ("things will get worse") Was found in the assessments at all three spatial levels. Spatial optimism bias ("things are better here than there") was found in the assessments of current environmental conditions in 15 Of 18 countries, but not in the assessments of the future. All countries except one exhibited temporal pessimism, but significant differences between them were common. Evaluations of current environmental conditions also differed by country. Citizens' assessments of current conditions, and the degree of comparative optimism, were strongly correlated with the expert panel's assessments of national environmental quality. Aside from the value of understanding global trends in environmental assessments, the results have important implications for environmental policy and risk management strategies. (C) 2008 Elsevier Ltd. All rights reserved

Computing the temperature dependence of effective CP violation in the standard model

Brauner T, Taanila O, Tranberg A, Vuorinen A. Computing the temperature dependence of effective CP violation in the standard model. JHEP. 2012;2012(11): 76.CP violation in the standard model originates from theCabibbo-Kobayashi-Maskawa mixing matrix. Upon integrating all fermions out ofthe theory, its effects are captured by a series of effective nonrenormalizableoperators for the bosonic gauge and Higgs fields. We compute the CP-violatingpart of the effective action to the leading nontrivial, sixth order in thecovariant gradient expansion as a function of temperature. In the limit of zerotemperature, our result addresses the discrepancy between two independentcalculations existing in the literature [1,2]. We find that CP violation in thestandard model is strongly suppressed at high temperature, but that at T<1GeVit may be relevant for certain scenarios of baryogenesis. We also identify aselected class of operators at the next, eighth order and discuss theconvergence of the covariant gradient expansion