76 research outputs found

    Hadronic Masses and Regge Trajectories

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    A comprehensive phenomenological analysis of experimental data and some theoretical models is presented here (for mesons) to critically discuss how Regge trajectory parameters depend on flavor. Through analytic continuation of physical trajectories (obtained from resonance data) into the space like region, we derive the suppression factor for heavy flavor production. The case of our D Regge exchange, both for D and Λc\Lambda_c production, is considered in some detail. Good agreement with data is reached confirming that indeed the slopes of heavier flavors decrease. This result suggests that the confinement potential has a substantial dependence on the quark masses. In a simple non-relativistic model, constrained to produce linear Regge trajectories, it is shown that a linear quark mass dependence is required (in the confinement part of the potential) in order for the slope to decrease in the appropriate way.Comment: 19 pages, 9 Figures, IV Table

    On asymmetry in inclusive pion production

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    On the basis of the mechanism proposed for one-spin asymmetries in inclusive hadron production we specify an xx--dependence of asymmetries in inclusive processes of pion production. The main role in generation of this asymmetry belongs to the orbital angular momentum ofquark-antiquark cloud in internal structure of constituent quarks. The xx--dependence of asymmetries in the charged pion production at large xx reflects the corresponding dependence of constituent quark polarization in the polarized proton.Comment: LaTeX, 8 pages, 3 figures. One figure added, as it appears in Phys. Rev.

    Crop variety management for climate adaptation supported by citizen science

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    Crop adaptation to climate change requires accelerated crop variety introduction accompanied by recommendations to help farmers match the best variety with their field contexts. Existing approaches to generate these recommendations lack scalability and predictivity in marginal production environments. We tested if crowdsourced citizen science can address this challenge, producing empirical data across geographic space that, in aggregate, can characterize varietal climatic responses. We present the results of 12,409 farmer-managed experimental plots of common bean (Phaseolus vulgaris L.) in Nicaragua, durum wheat (Triticum durum Desf.) in Ethiopia, and bread wheat (Triticum aestivum L.) in India. Farmers collaborated as citizen scientists, each ranking the performance of three varieties randomly assigned from a larger set. We show that the approach can register known specific effects of climate variation on varietal performance. The prediction of variety performance from seasonal climatic variables was generalizable across growing seasons. We show that these analyses can improve variety recommendations in four aspects: reduction of climate bias, incorporation of seasonal climate forecasts, risk analysis, and geographic extrapolation. Variety recommendations derived from the citizen science trials led to important differences with previous recommendations

    First results of the Instrumentation Line for the deep-sea ANTARES neutrino telescope

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    In 2005, the ANTARES Collaboration deployed and operated at a depth of 2500 m a so-called Mini Instrumentation Line equipped with Optical Modules (MILOM) at the ANTARES site. The various data acquired during the continuous operation from April to December 2005 of the MILOM confirm the satisfactory performance of the Optical Modules, their front-end electronics and readout system. as well as the calibration devices of the detector. The in situ measurement of the Optical Module time response yields a resolution better than 0.5 ns. The performance of the acoustic positioning system, which enables the spatial reconstruction of the ANTARES detector with a precision of about 10 cm, is verified. These results demonstrate that with the full ANTARES neutrino telescope the design angular resolution of better than 0.3 degrees can be realistically achieved

    MultiGLODS: global and local multiobjective optimization using direct search

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    The optimization ofmultimodal functions is a challenging task, in particular when derivatives are not available for use. Recently, in a directional direct search framework, a clever multistart strategy was proposed for global derivative-free optimization of single objective functions. The goal of the current work is to generalize this approach to the computation of global Pareto fronts for multiobjective multimodal derivative-free optimization problems. The proposed algorithm alternates between initializing new searches, using a multistart strategy, and exploring promising subregions, resorting to directional direct search. Components of the objective function are not aggregated and new points are accepted using the concept of Pareto dominance. The initialized searches are not all conducted until the end, merging when they start to be close to each other. The convergence of the method is analyzed under the common assumptions of directional direct search. Numerical experiments show its ability to generate approximations to the different Pareto fronts of a given problem.info:eu-repo/semantics/publishedVersio

    O impacto da imagem corporal alterada no paciente laringectomizado: relato de experiência

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    São relatadas as reações à primeira visão do estoma por dois pacientes laringectomizados. Na ausência de preparo psicológico para a alteração da imagem corporal, um paciente manifestou uma reação de crise que se refletiu negativamente na sua reabilitação posterior. Esta reação de crise pode ser evitada, em outro paciente, pelo preparo psicológico visando à alteração da imagem corporal pela cirurgia.The reactions of two laryngectomized patients to the first visual contact with the stoma are reported. In the absence of psychological preparation to the altered body image, one of the patient went through a crisis, situation which adversely influenced the rehabilitation process. This negative effect could be prevented through counselling and psychological preparation aimed to the alteration of body image caused by surgery
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