Collisions of Deformed Nuclei: A Path to the Far Side of the Superheavy Island

A detailed understanding of complete fusion cross sections in heavy-ion collisions requires a consideration of the effects of the deformation of the projectile and target. Our aim here is to show that deformation and orientation of the colliding nuclei have a very significant effect on the fusion-barrier height and on the compactness of the touching configuration. To facilitate discussions of fusion configurations of deformed nuclei, we develop a classification scheme and introduce a notation convention for these configurations. We discuss particular deformations and orientations that lead to compact touching configurations and to fusion-barrier heights that correspond to fairly low excitation energies of the compound systems. Such configurations should be the most favorable for producing superheavy elements. We analyse a few projectile-target combinations whose deformations allow favorable entrance-channel configurations and whose proton and neutron numbers lead to compound systems in a part of the superheavy region where alpha half-lives are calculated to be observable, that is, longer than 1 microsecond.Comment: 15 pages. LaTeX with iopconf.sty style file. Submitted to Nuclear Physics A. 25 figures not included here. PostScript version with figures available at http://t2.lanl.gov/pub/publications/publications.html or at ftp://t2.lanl.gov/pub/publications/cd

Second order expansions of action functionals of noncommutative gauge theories

Field theory and gauge theory on noncommutative spaces have been established as their own areas of research in recent years. The hope prevails that a noncommutative gauge theory will deliver testable experimental predictions and will thus be a serious candidate for an extension of the Standard Model. This note contains the results for expanded gauge theory actions on a noncommutative space with constant theta, up to second order, together with a discussion of the ambiguities of the expanded theory and how they affect the action.Comment: 17 page

Optimization of the extraordinary magnetoresistance in semiconductor-metal hybrid structures for magnetic-field sensor applications

Semiconductor-metal hybrid structures can exhibit a very large geometrical magnetoresistance effect, the so-called extraordinary magnetoresistance (EMR) effect. In this paper, we analyze this effect by means of a model based on the finite element method and compare our results with experimental data. In particular, we investigate the important effect of the contact resistance $\rho_c$ between the semiconductor and the metal on the EMR effect. Introducing a realistic $\rho_c=3.5\times 10^{-7} \Omega{\rm cm}^2$ in our model we find that at room temperature this reduces the EMR by 30% if compared to an analysis where $\rho_c$ is not considered.Comment: 4 pages; manuscript for MSS11 conference 2003, Nara, Japa

Economic voting and economic revolutionizing? The economics of incumbency changes in European democracies and revolutionary events in the Arab World

While people in democracies can vote their government out when they are discontent with its policies, those in dictatorships cannot do so. They can only attempt to expel the dictator via mass protests or revolutions. Based on a general cause-and-effect mechanism, the author analyzes whether such mass protests are more likely when the economic situation is poor and vote outs are more likely under bad economic conditions. The empirical analysis provides evidence of economic voting in the European democracies. On the other hand, the results for the Arab World show that economic revolutionizing does not occur there. For this reason, the economics of the Arab Spring are analyzed in greater detail. It can be concluded that bad policy is punished in democracies only. Therefore, by using positive analysis, the investigation demonstrates the malfunctioning of the political market in dictatorships. -- In diesem Aufsatz wird der Zusammenhang von Abwahl- bzw. Revolutionswahrscheinlichkeit und der ökonomischen Performance untersucht. Basierend auf einem allgemeinen Ursache-Wirkungs-Mechanismus werden die Thesen abgeleitet, dass eine schlechte ökonomische Performance zwar die Abwahlwahrscheinlichkeit erhöht, nicht jedoch die Revolutionswahrscheinlichkeit, da das Zustandekommen einer Revolution davon abhängt, ob das Kollektivgutproblem gelöst werden kann. Die empirische Analyse der europäischen Demokratien zeigt, dass eine schlechte ökonomische Performance vor einem Wahltermin häufiger mit einer Abwahl als mit einer Wiederwahl einhergeht. Die Untersuchung für Revolutionen und Aufstände in der arabischen Welt dagegen zeigt, dass dort kein solcher Zusammen-hang besteht, weshalb eine genauere Betrachtung der potentiellen ökonomischen Ursachen des arabischen Frühlings erfolgt. Ausgehend von der Annahme, dass die ökonomische Performance auch ein Maß für die Qualität der Regierungsarbeit ist, liefert die Analyse ein weiteres, nicht normatives Argument für die Überlegenheit von demokratischen Systemen gegenüber nicht-demokratischen, da schlechte Regierungsführung in letzeren nicht unmittelbar bestraft wird.economic voting,revolutionary events,Arab Spring,political economy,political protest,degree of democracy,dictatorship,Revolution,Abwahl,Arabischer Frühling,Demokratie,Diktatur,Neue politische Ökonomie