47 research outputs found

    Higgs Boson Decay into Hadronic Jets

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    The remarkable agreement of electroweak data with standard model (SM) predictions motivates the study of extensions of the SM in which the Higgs boson is light and couples in a standard way to the weak gauge bosons. Postulated new light particles should have small couplings to the gauge bosons. Within this context it is natural to assume that the branching fractions of the light SM-like Higgs boson mimic those in the standard model. This assumption may be unwarranted, however, if there are non-standard light particles coupled weakly to the gauge bosons but strongly to the Higgs field. In particular, the Higgs boson may effectively decay into hadronic jets, possibly without important bottom or charm flavor content. As an example, we present a simple extension of the SM, in which the predominant decay of the Higgs boson occurs into a pair of light bottom squarks that, in turn, manifest themselves as hadronic jets. Discovery of the Higgs boson remains possible at an electron-positron linear collider, but prospects at hadron colliders are diminished substantially.Comment: 30 pages, 7 figure

    Red Queen Coevolution on Fitness Landscapes

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    Species do not merely evolve, they also coevolve with other organisms. Coevolution is a major force driving interacting species to continuously evolve ex- ploring their fitness landscapes. Coevolution involves the coupling of species fit- ness landscapes, linking species genetic changes with their inter-specific ecological interactions. Here we first introduce the Red Queen hypothesis of evolution com- menting on some theoretical aspects and empirical evidences. As an introduction to the fitness landscape concept, we review key issues on evolution on simple and rugged fitness landscapes. Then we present key modeling examples of coevolution on different fitness landscapes at different scales, from RNA viruses to complex ecosystems and macroevolution.Comment: 40 pages, 12 figures. To appear in "Recent Advances in the Theory and Application of Fitness Landscapes" (H. Richter and A. Engelbrecht, eds.). Springer Series in Emergence, Complexity, and Computation, 201

    Randomness Increases Order in Biological Evolution

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    n this text, we revisit part of the analysis of anti-entropy in Bailly and Longo (2009} and develop further theoretical reflections. In particular, we analyze how randomness, an essential component of biological variability, is associated to the growth of biological organization, both in ontogenesis and in evolution. This approach, in particular, focuses on the role of global entropy production and provides a tool for a mathematical understanding of some fundamental observations by Gould on the increasing phenotypic complexity along evolution. Lastly, we analyze the situation in terms of theoretical symmetries, in order to further specify the biological meaning of anti-entropy as well as its strong link with randomness

    Dynamics of Local Search Trajectory in Traveling Salesman Problem

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    This paper investigates dynamics of a local search trajectory generated by running the Or-opt heuristic on the traveling salesman problem. This study evaluates the dynamics of the local search heuristic by estimating the correlation dimension for the search trajectory, and finds that the local heuristic search process exhibits the transition from high-dimensional stochastic to low-dimensional chaotic behavior. The detection of dynamical complexity for a heuristic search process has both practical as well as theoretical relevance. The revealed dynamics may cast new light on design and analysis of heuristics and result in the potential for improved search process.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45818/1/10732_2005_Article_3604.pd
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