4,427 research outputs found
Antiproton-proton partial-wave analysis below 925 MeV/c
A partial-wave analysis of all antiproton-proton scattering data below 925
MeV/c antiproton laboratory momentum is presented. The method used is adapted
from the Nijmegen phase-shift analyses of pp and np scattering data. The
Nijmegen 1993 antiproton-proton database, consisting of 3646 antiproton-proton
scattering data, is presented and discussed. The best fit to this database
results in chi^2_min/Ndata = 1.043. The pseudovector coupling constant of the
charged pion to nucleons is determined to be (f_c)^2 = 0.0732(11) at the pion
pole, where the error is statistical.Comment: Report THEF-NYM 93.02 42 pages REVTeX, 7 separate postscript figures
appended. Accepted for publication in Phys. Rev.
Tools for climate change adaptation in water management - inventory and assessment of methods and tools
This report summarizes an inventory of methods and tools for assessing climate change impacts, vulnerability and adaptation options, focusing on the water sector. Two questions are central: What are the opportunities for international applications of Dutch methods and tools? And: Which methods and tools available abroad are suitable for application in The Netherlands
Partial-Wave Analyses of all Proton-Proton and Neutron-Proton Data Below 500 MeV
In 1993 the Nijmegen group published the results of energy-dependent
partial-wave analyses (PWAs) of the nucleon-nucleon (NN) scattering data for
laboratory kinetic energies below Tlab=350 MeV (PWA93). In this talk some
general aspects, but also the newest developments on the Nijmegen NN PWAs are
reported. We have almost finished a new energy-dependent PWA and will discuss
some typical aspects of this new PWA; where it differs from PWA93, but also
what future developments might be, or should be.Comment: Presentation at the 19th European Conference on Few-Body Problems in
Physics, Groningen, The Netherlands, 23-27 August 2004. 4 pages REVTeX4, no
figure
The Status of the Pion-Nucleon Coupling Constant
A review is given of the various determinations of the different piNN
coupling constants in analyses of the low-energy pp, np, pbarp, and pi-p
scattering data. The most accurate determinations are in the energy-dependent
partial-wave analyses of the NN data. The recommended value is f^2 = 0.075 . A
recent determination of f^2 by the Uppsala group from backward np cross
sections is shown to be model dependent and inaccurate, and therefore
completely uninteresting. We also argue that an accurate determination of f^2
using pp forward dispersion relations is not a realistic option.Comment: 19 pages, latex2e with a4wide.sty, more information is available at
http://NN-OnLine.sci.kun.nl . Invited talk at FBXV, Groningen, The
Netherlands, July 22-26, 1997. Invited talk at MENU97, Vancouver, B.C.,
Canada, July 28 - August 1, 199
The nucleon-sigma coupling constant in QCD Sum Rules
The external-field QCD Sum Rules method is used to evaluate the coupling
constant of the light isoscalar-scalar meson (``'' or \epsilon) to the
nucleon. The contributions that come from the excited nucleon states and the
response of the continuum threshold to the external field are calculated. The
obtained value of the coupling constant is compatible with the large value
required in one-boson exchange potential models of the two-nucleon interaction.Comment: 11 pages, 4 figure
Deuteron Dipole Polarizabilities and Sum Rules
The scalar, vector, and tensor components of the (generalized) deuteron
electric polarizability are calculated, as well as their logarithmic
modifications. Several of these quantities arise in the treatment of the
nuclear corrections to the deuterium Lamb shift and the deuterium hyperfine
structure. A variety of second-generation potential models are used and a
(subjective) error is assigned to the calculations. The zero-range
approximation is used to analyze a subset of the results, and a simple
relativistic version of this approximation is developed.Comment: 14 pages, LaTex - submitted to Physical Review
Report on uncertainty methods
The issue of uncertainty is critical for climate change science and policy. A great deal of research analysis has gone into identifying the scope and character of uncertainty in climate change itself, in how analysts and assessment teams can and should communicate that uncertainty to policy- and decision-makers, and how policy- and decision-makers can then incorporate nowledge about the sources and magnitude of uncertainty in their choices. The primary purpose of this deliverable is to summarize that literature, and to synthesize it in a manner that is useful for the Mediation project, namely in improving the practice of assessing adaptaion needs and options, and in building a useful decision-support platform or system. The report starts with a user-driven focus, summarizing the literatures on both descriptive and normative models of decision-making under uncertainty, in order to identify the most effective and esential information inputs for each of these models. The report then summarizes some of the main guidance documents on communicating uncertanty, prepared for or in use by the Intergovernmental Panel on Climate Change, the United States government, and the Dutch government. Fially, the report synthesizes these previous studies for use in the Mediation project and its users by focusing on three essential characteristics of uncertainty communication: parsimony, personalization, and practicality. It identifies specific strategies for using these three criteria to ensure that assessments for climate adaptation are salient, credible, and legitimate, and thus ultimately construtive inputs into policy- and decision-making
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