Future Dispute System Design: Ethical Imperatives, Millennial and Beyond

Published in cooperation with the American Bar Association Section of Dispute Resolutio

The piNN vertex function in a meson-theoretical model

The piNN vertex function is calculated within a dispersion theoretical approach, including both pi-rho and pi-sigma intermediate states, where the sigma meson is an abbreviation for a correlated pion pair in a relative S-wave with isospin I=0. A strong coupling between the pi-sigma and the pi-rho states is found. This leads to a softening of the piNN form factor. In a monopole parameterization, a cut-off Lambda=800 MeV is obtained as compared to Lambda=1000 MeV using pi-rho intermediate states only.Comment: 6 pages, 8 figure

Near threshold Lambda and Sigma production in pp collisions

A model calculation for the reactions $pp\to p\Lambda K^+$ and $pp\to N\Sigma K$ near their thresholds is presented. It is argued that the experimentally observed strong suppression of $\Sigma^0$ production compared to $\Lambda$ production at the same excess energy could be due to a destructive interference between the $\pi$ and $K$ exchange contributions in the reaction $pp\to p\Sigma^0 K^+$. Predictions for $pp\to p\Sigma^+ K^0$ and $pp\to n\Sigma^+ K^+$ are given.Comment: 3 pages, 1 figure, uses espcrc1.sty, contribution presented at the 16th International Conference on Few-Body Problems in Physics, Taipei, Taiwan, 6-10 March 200

Metagenomic analysis of nitrogen and methane cycling in the Arabian Sea oxygen minimum zone

Oxygen minimum zones (OMZ) are areas in the global ocean where oxygen concentrations drop to below one percent. Low oxygen concentrations allow alternative respiration with nitrate and nitrite as electron acceptor to become prevalent in these areas, making them main contributors to oceanic nitrogen loss. The contribution of anammox and denitrification to nitrogen loss seems to vary in different OMZs. In the Arabian Sea, both processes were reported. Here, we performed a metagenomics study of the upper and core zone of the Arabian Sea OMZ, to provide a comprehensive overview of the genetic potential for nitrogen and methane cycling. We propose that aerobic ammonium oxidation is carried out by a diverse community of Thaumarchaeota in the upper zone of the OMZ, whereas a low diversity of Scalindua-like anammox bacteria contribute significantly to nitrogen loss in the core zone. Aerobic nitrite oxidation in the OMZ seems to be performed by Nitrospina spp. and a novel lineage of nitrite oxidizing organisms that is present in roughly equal abundance as Nitrospina. Dissimilatory nitrate reduction to ammonia (DNRA) can be carried out by yet unknown microorganisms harbouring a divergent nrfA gene. The metagenomes do not provide conclusive evidence for active methane cycling; however, a low abundance of novel alkane monooxygenase diversity was detected. Taken together, our approach confirmed the genomic potential for an active nitrogen cycle in the Arabian Sea and allowed detection of hitherto overlooked lineages of carbon and nitrogen cycle bacteria

Baryon vector and axial content up to the 7Q component

We have used the light-cone formulation of Chiral-Quark Soliton Model to investigate the vector and axial content of octet, decuplet and the hypothetical antidecuplet in the flavor SU(3) symmetry limit. We have extended previous works by computing the 7Q contribution to vector and axial charges for the octet and antidecuplet but stayed at the 5Q sector for the decuplet where the full computation needs much more time. As expected the 7Q component has a weaker impact on the quantities but still changes them by a few percent. We give also a detailed decomposition of those charges into flavor, valence quark, sea quark and antiquark contributions. Many of them are of course not (yet) measured or estimated and constitute then a theoretical estimation. Among the different interesting observations made in this work are the explicit quadrupole deformation of decuplet baryons due to the pion field and the sum of quark spins larger than the pentaquark one.Comment: 34 pages, 7 figures and 17 tables, revised and more explicit versio

Pion-nucleon scattering in a meson-exchange model

The piN interaction is studied within a meson-exchange model and in a coupled-channels approach which includes the channels piN, etaN, as well as three effective pipiN channels, namely, rhoN, piDelta, and sigmaN. Starting out from an earlier model of the Julich group systematic improvements in the dynamics and in some technical aspects are introduced. With the new model an excellent quantitative reproduction of the piN phase shifts and inelasticity parameters in the energy region up to 1.9 GeV and for total angular momenta Jless than or equal to3/2 is achieved. Simultaneously, good agreement with data for the total and differential piN-->etaN transition cross sections is obtained. The connection of the piN dynamics in the S-11 partial wave with the reaction piN-->etaN is discussed

Angular asymmetries in the reactions pp \to d\pi^+\eta and pn \to d\pi^0\eta and a_0-f_0 mixing

The reactions pp\to d\pi^+\eta and pn\to d\pi^0\eta are of special interest for investigating the a_0(980) (J^P=0^+) resonance in the process NN \to da_0 \to d\pi\eta. We study some aspects of those reactions within a general formalism and also in a concrete phenomenological model. In particular, it is shown that the presence of nonresonant (i.e. without excitation of the a_0 resonance) contributions to these reactions yields nonvanishing values for specific polarization observables, i.e. to effects like those generated by a_0-f_0 mixing. An experimental determination of these observables for the reaction pp\to d\pi^+\eta would provide concrete information on the magnitude of those nonresonant contributions to \pi\eta production. We discuss also the possibility of extracting information about a_0-f_0 mixing from the reaction pn \to d\pi^0\eta with polarized proton beam.Comment: 14 pages, 3 figure

Opportunities to Intercalibrate Radiometric Sensors From International Space Station

Highly accurate measurements of Earth's thermal infrared and reflected solar radiation are required for detecting and predicting long-term climate change. We consider the concept of using the International Space Station to test instruments and techniques that would eventually be used on a dedicated mission such as the Climate Absolute Radiance and Refractivity Observatory. In particular, a quantitative investigation is performed to determine whether it is possible to use measurements obtained with a highly accurate reflected solar radiation spectrometer to calibrate similar, less accurate instruments in other low Earth orbits. Estimates of numbers of samples useful for intercalibration are made with the aid of year-long simulations of orbital motion. We conclude that the International Space Station orbit is ideally suited for the purpose of intercalibration

Polarization phenomena in the reaction NN to NNpi near threshold

First calculations for spin-dependent observables of the reactions $pp \to pp\pi^0$, $pp \to pn\pi^+$ and $pp \to d\pi^+$ near threshold are presented, employing the J\"ulich model for pion production. The influence of resonant (via the excitation of the $\Delta (1232)$) and non-resonant p-wave pion production mechanisms on these observables is examined. For the reactions $pp \to pn\pi^+$ and $pp \to d\pi^+$ nice agreement of our predictions with the presently available data on spin correlation coefficents is observed whereas for $pp \to pp\pi^0$ the description of the data is less satisfying.Comment: 10 pages, 4 figure