143 research outputs found

    Domesticating forests : how farmers manage forest resources

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    Local people in South-east Asia are often cited as skilled forest managers. It is barely acknowledged that an essential part of this forest management does not concern natural forests, but forests that have been planted, often after the removal of pre-existing natural forests; forests that are cultivated not by professional foresters, but by sedentary or swidden farmers, on their farmlands; forests that are based not on exotic, fast-growing trees, but on local tree species, and harbour an incredible variety of plant and animal species. This book concentrates on forest cultivation by smallholder farmers in South-east Asia, not only because it constitutes altogether the most original and lesser known aspect of local forest management in the region, but also because, it represents the most promising field for the design of alternative strategies for the management of forest resources and forest lands. Natural forests are still present and actively managed in the region. So, why do people cut natural forests to replant the same species of forest trees they have just chopped down? Why have professional foresters, or the decision-makers in forest management, never seriously considered these examples of indigenous forest culture, however sustainable and profitable they may be? Many elements of the answer to these questions are given in this book, which is built on the conclusions of 10 years of multidisciplinary research and analysis on these systems. It shows how forest culture by farmers constitutes a strategy that questions the practical, conceptual and legal aspects of conventional forest management. It speaks for more scientific and political support to these systems, because they are altogether neglected, endangered and full of potential. Further it explains a why it is important to consider these examples as interesting alternative models to either forest extraction or specialized forest plantations, especially in the present context of depletion of natural forests all over the planet. Can the transfer of these original examples to other parts of the world be achieved? How can it be successful? This book helps to answer these important questions

    Lepton Flavor Violation: Constraints from exotic muon to electron conversion

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    The exotic neutrinoless Ό−−e−\mu^- - e^- nuclear conversion is studied within the conventional extensions of the standard model as well as in the minimal supersymmetric (SUSY) models with and without R-parity conservation. The dependence of the Ό−−e−\mu^- - e^- conversion rates on the nucleon and nuclear structure is consistently taken into account. Using our calculated transition matrix elements and the available experimental data on the branching ratio RÎŒe−R_{\mu e^-} for 48^{48}Ti and 208^{208}Pb as well as the expected experimental sensitivity for 27^{27}Al employed as a target in the planned at Brookhaven Ό−−e−\mu^--e^- conversion (MECO) experiment, we extract very severe constraints for the flavor violation parameters. We especially emphasize on the constraints resulting for SUSY R-parity violating parameters.Comment: 14 pages, 2 figures. Based on the Invited talk given by T.S. Kosmas at the International Conference on Non-Accelerator New Physics(NANP'99), Dubna, Russia, 199

    Neutrinoless Double ÎČ\beta-Decay: Status and Future

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    A brief summary of the status of neutrino masses, mixing and oscillations is presented. Neutrinoless double ÎČ\beta-decay is considered. Predictions for the effective Majorana mass are reviewed. A possible test of the calculations of nuclear matrix elements of the 0ÎœÎČÎČ0\nu\beta\beta-decay is proposed.Comment: A report at the International conference ``Non-Accelerator New Physics'' NANP05 Dubna, Russia, June 20-25, 200

    Production of Triply Charmed Ωccc\Omega_{ccc} Baryons in e+e−e^+e^- Annihilation

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    The total and differential cross sections for the production of triply charmed Ωccc\Omega_{ccc} baryons in e+e−e^{+}e^{-} annihilation are calculated at the ZZ-boson pole.Comment: 13 pages, 2 figure

    Neutrino Physics at the Turn of the Millenium

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    Recent solar & atmospheric nu-data strongly indicate need for physics beyond the Standard Model. I review the ways of reconciling them in terms of 3-nu oscillations. Though not implied by data, bi-maximal nu-mixing models emerge as a possibility. SUSY with broken R-parity provides an attractive way to incorporate it, opening the possibility of testing nu-anomalies at high- energy colliders such as the LHC or at the upcoming long-baseline or nu- factory experiments. Reconciling, in addition, the LSND hint requires a fourth, light sterile neutrino, nus. The simplest are the most symmetric scenarios, in which 2 of the 4 neutrinos are maximally-mixed and lie at the LSND scale, while the others are at the solar scale. The lightness of nus, the nearly maximal atmospheric mixing, and the solar/atmospheric splittings all follow naturally from the assumed lepton-number symmetry and its breaking. These basic schemes can be distinguished at neutral-current-sensitive solar & atmospheric neutrino experiments such as SNO. However underground experiments have not yet proven neutrino masses, as there are many alternatives. For example flavour changing interactions can play an important role in the explanation of solar and contained atmospheric data and could be tested e.g through \mu \to e + \gamma, \mu-e conversion in nuclei, unaccompanied by neutrino-less double beta decay. Conversely, a short-lived numu might play a role in the explanation of the atmospheric data. Finally, in the presence of a nus, a long-lived heavy nutau could delay the time at which the matter and radiation contributions to the energy density of the Universe become equal, reducing density fluctuations on smaller scales, thus saving the standard CDM scenario, while the light nue, numu and nus would explain the solar & atmospheric data.Comment: Invited talk at 2nd International Conference on Non-Accelerator New Physics (NANP-99), Dubna, June 28 - July 3, 199

    From AMANDA to IceCube

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    The first string of the neoteric high energy neutrino telescope IceCube successfully began operating in January 2005. It is anticipated that upon completion the new detector will vastly increase the sensitivity and extend the reach of AMANDA to higher energies. A discussion of the IceCube's discovery potential for extra-terrestrial neutrinos, together with the prospects of new physics derived from the ongoing AMANDA research will be the focus of this paper. Preliminary results of the first antarctic high energy neutrino telescope AMANDA searching in the muon neutrino channel for localized and diffuse excess of extra-terrestrial neutrinos will be reviewed using data collected between 2000 and 2003. Neutrino flux limits obtained with the all-flavor dedicated UHE and cascade analyses will be described. A first neutrino spectrum above one TeV in agreement with atmospheric neutrino flux expectations and no extra-terrestrial contribution will be presented, followed by a discussion of a limit for neutralino CDM candidates annihilating in the center of the Sun.Comment: 15 pages, 8 figures Invited talk contribution at 5th International Conference on Non-accelerator New Physics (NANP 05), Dubna, Russia, 20-25 Jun 200

    Antikaon angular distributions in the reaction γd→K−Θ+p→K−K+np{\gamma}d \to K^-{\Theta}^+p \to K^-K^+np near the threshold and the parity of the Θ+{\Theta}^+ pentaquark

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    Within spectator model we study the reaction Îłd→K−Θ+p→K−K+np{\gamma}d \to K^-{\Theta}^+p \to K^-K^+np in the threshold energy region. We present the predictions for the exclusive and inclusive antikaon angular distributions in the laboratory system for this reaction calculated for two possible parity states of the Θ+{\Theta}^+ resonance at 1.5 and 1.75 GeV beam energies with and without imposing the relevant kinematical cuts on those parts of the sampled phase space where contribution from the main background sources associated with the ϕ(1020){\phi}(1020), Λ(1520){\Lambda}(1520) production as well as with the K−pK^-p--rescattering in the final state, is expected to be dominant. We show that under chosen kinematics these distributions are sensitive to the Θ+{\Theta}^+ parity and, therefore, can be used as a filter for the determination of its parity.Comment: 18 pages, 8 figures; will be published in Phys.Atom.Nucl_4_200
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