A New Approach to Nuclear Collisions at RHIC Energies

We present a new parton model approach for nuclear collisions at RHIC energies (and beyond). It is a selfconsistent treatment, using the same formalism for calculating cross sections like the total and the inelastic one and, on the other hand, particle production. Actually, the latter one is based on an expression for the total cross section, expanded in terms of cut Feynman diagrams. Dominant diagrams are assumed to be composed of parton ladders between any pair of nucleons, with ordered virtualities from both ends of the ladder.Comment: 8 pages, 3 figures (proceedings Quark Matter 99

On the integrability of halo dipoles in gravity

We stress that halo dipole components are nontrivial in core-halo systems in both Newton's gravity and General Relativity. To this end, we extend a recent exact relativistic model to include also a halo dipole component. Next, we consider orbits evolving in the inner vacuum between a monopolar core and a pure halo dipole and find that, while the Newtonian dynamics is integrable, its relativistic counterpart is chaotic. This shows that chaoticity due only to halo dipoles is an intrinsic relativistic gravitational effect.Comment: 9 pages, REVTEX, two postscript figures include

Semihard Interactions in Nuclear Collisions Based on a Unified Approach to High Energy Scattering

Our ultimate goal is the construction of a model for interactions of two nuclei in the energy range between several tens of GeV up to several TeV per nucleon in the centre-of-mass system. Such nuclear collisions are very complex, being composed of many components, and therefore some strategy is needed to construct a reliable model. The central point of our approach is the hypothesis, that the behavior of high energy interactions is universal (universality hypothesis). So, for example, the hadronization of partons in nuclear interactions follows the same rules as the one in electron-positron annihilation; the radiation of off-shell partons in nuclear collisions is based on the same principles as the one in deep inelastic scattering. We construct a model for nuclear interactions in a modular fashion. The individual modules, based on the universality hypothesis, are identified as building blocks for more elementary interactions (like e^+ e^-, lepton-proton), and can therefore be studied in a much simpler context. With these building blocks under control, we can provide a quite reliable model for nucleus-nucleus scattering, providing in particular very useful tests for the complicated numerical procedures using Monte Carlo techniques.Comment: 10 pages, no figures; Proc. of the ``Workshop on Nuclear Matter in Different Phases and Transitions'', Les Houches, France, March 31 - April 10, 199

A New String Model: NEXUS 3

After discussing conceptual problems with the conventional string model, we present a new approach, based on a theoretically consistent multiple scattering formalism. First results for proton-proton scattering at 158 GeV are discussed.Comment: invited talk given at the 9th Winter Workshop on Nuclear Dynamics, Breckenridge, Colorado, February 9 - 14, 200

Universal scaling behavior of the single electron box in the strong tunneling limit

We perform a numerical analysis of recently proposed scaling functions for the single electron box. Specifically, we study the ``magnetic'' susceptibility as a function of tunneling conductance and gate charge, and the effective charging energy at zero gate charge as a function of tunneling conductance in the strong tunneling limit. Our Monte Carlo results confirm the accuracy of the theoretical predictions.Comment: Published versio

Phase transitions and the internal noise structure of nonlinear Schr\"odi nger equation solitons

We predict phase-transitions in the quantum noise characteristics of systems described by the quantum nonlinear Schr\"odinger equation, showing them to be related to the solitonic field transition at half the fundamental soliton amplitude. These phase-transitions are robust with respect to Raman noise and scattering losses. We also describe the rich internal quantum noise structure of the solitonic fields in the vicinity of the phase-transition. For optical coherent quantum solitons, this leads to the prediction that eliminating the peak side-band noise due to the electronic nonlinearity of silica fiber by spectral filtering leads to the optimal photon-number noise reduction of a fundamental soliton.Comment: 10 pages, 5 figure

Assessment of on-farm, market and wild food diversity in three agro-ecological zones of Western Kenya

Poster presented at Tropentag 2014. International Conference on Research on Food Security, Natural Resource Management and Rural Development. "Bridging the Gap between Increasing Knowledge and Decreasing Resources" Prague (Czech Republic) Sep 17-19 2014