Ionization of helium by slow antiproton impact: total and differential cross sections

We theoretically investigate the single and double ionization of the He atom by antiproton impact for projectile energies ranging from $3$~keV up to $1000$~keV. We obtain accurate total cross sections by directly solving the fully correlated two-electron time-dependent Schr\"odinger equation and by performing classical trajectory Monte-Carlo calculations. The obtained quantum-mechanical results are in excellent agreement with the available experimental data. Along with the total cross sections, we also present the first fully \textit{ab initio} doubly differential data for single ionization at 10 and 100~keV impact energies. In these differential cross sections we identify the binary-encounter peak along with the anticusp minimum. Furthermore, we also point out the importance of the post-collisional electron-projectile interaction at low antiproton energies which significantly suppresses electron emission in the forward direction

Structural change, economic growth and bazaar effects in the single EU market

This paper analyzes the link between structural change, growth and bazaar effects in the context of open economies. At first we consider the theoretical basis of structural change and discuss the interdependencies between trade, foreign direct investment and innovation dynamics. The empirical analysis puts the focus on traits of innovation and structural change in selected countries. As regards the hypothesis of a bazaar effect we distinguish between gross effects and net effects. The statistics and the analysis of input-output-tables does not provide evidence that bazaar effects would be a critical problem for Germany or other EU countries. JEL Classification : F4, F43, L16, O3Dieser Beitrag thematisiert den Zusammenhang von Strukturwandel, Wachstum und Basareffekten im Kontext internationaler Märkte. Zunächst wird die theoretische Basis der Analyse des Strukturwandels in offenen Volkswirtschaften dargestellt. Dabei ist die Verbindung von Außenhandel, Direktinvestitionen und Innovationsdynamik wesentlich. In der empirischen Analyse werden ausgewählte Innovationsentwicklungen und die Dynamik des Strukturwandels für ausgewählte Länder dargestellt. Schließlich wird auf die Hypothese zum Basareffekt eingegangen wobei ein Bruttoeffekt und ein Nettoeffekt unterschieden werden. Die Statistiken bzw. die Auswertungen der Input-Output-Tabellen zeigen keine Evidenz dafür, dass in Deutschland und anderen EU-Ländern Basareffekte ein problematisches Phänomen darstellten. JEL Classification : F4, F43, L16, O

Correlation Between the Deuteron Characteristics and the Low-energy Triplet np Scattering Parameters

The correlation relationship between the deuteron asymptotic normalization constant, $A_{S}$, and the triplet np scattering length, $a_{t}$, is investigated. It is found that 99.7% of the asymptotic constant $A_{S}$ is determined by the scattering length $a_{t}$. It is shown that the linear correlation relationship between the quantities $A_{S}^{-2}$ and $1/a_{t}$ provides a good test of correctness of various models of nucleon-nucleon interaction. It is revealed that, for the normalization constant $A_{S}$ and for the root-mean-square deuteron radius $r_{d}$, the results obtained with the experimental value recommended at present for the triplet scattering length $a_{t}$ are exaggerated with respect to their experimental counterparts. By using the latest experimental phase shifts of Arndt et al., we obtain, for the low-energy scattering parameters ($a_{t}$, $r_{t}$, $P_{t}$) and for the deuteron characteristics ($A_{S}$, $r_{d}$), results that comply well with experimental data.Comment: 19 pages, 1 figure, To be published in Physics of Atomic Nucle