Non-global logarithms in jet and isolation cone cross sections

Starting from a factorization theorem in effective field theory, we derive a parton-shower equation for the resummation of non-global logarithms. We have implemented this shower and interfaced it with a tree-level event generator to obtain an automated framework to resum the leading logarithm of non-global observables in the large-$N_c$ limit. Using this setup, we compute gap fractions for dijet processes and isolation cone cross sections relevant for photon production. We compare our results with fixed-order computations and LHC measurements. We find that naive exponentiation is often not adequate, especially when the vetoed region is small, since non-global contributions are enhanced due to their dependence on the veto-region size. Since our parton shower is derived from first principles and based on renormalization-group evolution, it is clear what ingredients will have to be included to perform resummations at subleading logarithmic accuracy in the future.Comment: 39 pages, 13 figures. v2: journal version with new result (4.18) for narrow isolation cone

Europe and the large solar system projects

Europe made great advances in planetary exploration with the space probe to Halley's comet. The current and future plans incorporated in the Horizon 2000 core programme are minimal but balanced. They are currently threatened by lack of resources: it would be unforgivable to leave this field to the large space powers no

New environmental regionalism and sustainable development

AbstractThis contribution is based on a set of reflections presented at the REGov Workshop. These reflections were offered as part of a panel discussion around the topic “New environmental regionalism.” Additional presentations provided in the context of this panel discussion include those of William Jackson, International Union for the Conservation of Nature (this volume) and Frédéric Giraut, University of Geneva (this volume). Webcasts of all presentations are available at http://www.reg-observatory.org/outputs.html