5,830 research outputs found
The Cosmic Ray Antiproton Background for AMS-02
The AMS-02 experiment is measuring the cosmic ray antiproton flux with high
precision. The interpretation of the upcoming data requires a thorough
understanding of the secondary antiproton background. In this work, we employ
newly available data of the NA49 experiment at CERN, in order to recalculate
the antiproton source term arising from cosmic ray spallations on the
interstellar matter. We systematically account for the production of
antiprotons via hyperon decay and discuss the possible impact of isospin
effects on antineutron production. A detailed comparison of our calculation
with the existing literature as well as with Monte Carlo based evaluations of
the antiproton source term is provided. Our most important result is an updated
prediction for the secondary antiproton flux which includes a realistic
assessment of the particle physics uncertainties at all energies.Comment: 24 pages, 10 figures, source term and secondary flux available in the
ancillary file
Utility based regional purchasing power parities
Calculation of purchasing power parities based on observed consumer behaviour typically relies on the existence of some kind of 'international preferences'. We argue that this unrealistic assumption can be abandoned in 'regional' studies of purchasing power, where prices in both territories under study might differ only slightly. Drawing on recent results for the derivation of equivalence scales, we develop a model of regional purchasing power and discuss several procedures for testing model specification. The model is applied to data of the German Income and Expenditure Survey 1998 to estimate the wedge between purchasing power in the western and eastern part of Germany. --
Ifosfamide with regional hyperthermia in soft-tissue sarcomas
For high-risk soft tissue sarcomas (HR-STS) of adults, new treatment strategies are needed to improve outcome with regard to local control and overall survival. Therefore, systemic chemotherapy has been integrated either after (adjuvant) or before (neoadjuvant) optimal local treatment by surgery and radiotherapy in HR-STS. The combination with regional hyperthermia as a new treatment strategy seems to open a new therapeutic window. Copyright (C) 2003 S. Karger AG, Basel
Natural Inflation and Low Energy Supersymmetry
Natural (axionic) inflation provides a well-motivated and predictive scheme
for the description of the early universe. It leads to sizeable primordial
tensor modes and thus a high mass scale of the inflationary potential. Naively
this seems to be at odds with low (TeV) scale supersymmetry, especially when
embedded in superstring theory. We show that low scale supersymmetry is
compatible with natural (high scale) inflation. The mechanism requires the
presence of two axions that are provided through the moduli of string theory.Comment: 15 pages, 4 figure
Modulated Natural Inflation
We discuss some model-independent implications of embedding (aligned) axionic
inflation in string theory. As a consequence of string theoretic duality
symmetries the pure cosine potentials of natural inflation are replaced by
modular functions. This leads to "wiggles" in the inflationary potential that
modify the predictions with respect to CMB-observations. In particular, the
scalar power spectrum deviates from the standard power law form. As a
by-product one can show that trans-Planckian excursions of the aligned
effective axion are compatible with the weak gravity conjecture.Comment: 8 pages, 6 figure
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