Translation of Time-Reversal Violation in the Neutral K-Meson System into a Table-Top Mechanical System

Weak interactions break time-reversal (T) symmetry in the two-state system of neutral K mesons. We present and discuss a two-state mechanical system, a Foucault-type pendulum on a rotating table, for a full representation of K0 K0bar transitions by the pendulum motions including T violation. The pendulum moves with two different oscillation frequencies and two different magnetic dampings. Its equation of motion is identical with the differential equation for the real part of the CPT-symmetric K-meson wave function. The pendulum is able to represent microscopic CP and T violation with CPT symmetry owing to the macroscopic Coriolis force which breaks the symmetry under reversal-of-motion. Video clips of the pendulum motions are shown as supplementary material.Comment: 11 pages, 5 figures, 1 external url with video clip

Electronic and Thermoelectric Properties of RuIn_{3-x}A_{x} (A = Sn, Zn)

Recently, we reported [M. Wagner et al., J. Mater. Res. 26, 1886 (2011)] transport measurements on the semiconducting intermetallic system RuIn3 and its substitution derivatives RuIn_{3-x}A_{x} (A = Sn, Zn). Higher values of the thermoelectric figure of merit (zT = 0.45) compared to the parent compound were achieved by chemical substitution. Here, using density functional theory based calculations, we report on the microscopic picture behind the measured phenomenon. We show in detail that the electronic structure of the substitution variants of the intermetallic system RuIn_{3-x}A_{x} (A = Sn, Zn) changes in a rigid-band like fashion. This behavior makes possible the fine tuning of the substitution concentration to take advantage of the sharp peak-like features in the density of states of the semiconducting parent compound. Trends in the transport properties calculated using the semi-classical Boltzmann transport equations within the constant scattering time approximation are in good agreement with the former experimental results for RuIn_{3-x}Sn_{x}. Based on the calculated thermopower for the p-doped systems, we reinvestigated the Zn-substituted derivative and obtained ZnO-free RuIn_{3-x}Zn_{x}. The new experimental results are consistent with the calculated trend in thermopower and yield large zT value of 0.8.Comment: PRB Accepted, 11 pages, 10 figure

Demonstration of K-Kbar, B-Bbar, and D-Dbar Transitions with a Pair of Coupled Pendula

A setup of two coupled and damped pendula is used to demonstrate the main features of transitions beween neutral K, D, B mesons and their respective antiparticles, including CP violation in K Kbar transitions. The transitions are described by two-state Schr\"odinger equations. Since the real parts of their solutions obey the same differential equations as the pendula coordinates, the pendulum motions can be used to represent the meson transitions. Video clips of the motions are attached as supplementary material.Comment: 15 pages, 6 figure

Perspectives of Long-Haul WDM Transmission Systems Based on Phase-Insensitive Fiber-Optic Parametric Amplifiers

International audienceThe deployment of phase-insensitive fiber-optic parametric amplifiers (PI-FOPAs) as inline amplifiers in long-haul WDM transmission systems is discussed, and it is outlined how to design PI-FOPAs to be a valuable upgrade option for this application

Determination of the Michel Parameters rho, xi, and delta in tau-Lepton Decays with tau --> rho nu Tags

Using the ARGUS detector at the $e^+ e^-$ storage ring DORIS II, we have measured the Michel parameters $\rho$, $\xi$, and $\xi\delta$ for $\tau^{\pm}\to l^{\pm} \nu\bar\nu$ decays in $\tau$-pair events produced at center of mass energies in the region of the $\Upsilon$ resonances. Using $\tau^\mp \to \rho^\mp \nu$ as spin analyzing tags, we find $\rho_{e}=0.68\pm 0.04 \pm 0.08$, $\xi_{e}= 1.12 \pm 0.20 \pm 0.09$, $\xi\delta_{e}= 0.57 \pm 0.14 \pm 0.07$, $\rho_{\mu}= 0.69 \pm 0.06 \pm 0.08$, $\xi_{\mu}= 1.25 \pm 0.27 \pm 0.14$ and $\xi\delta_{\mu}= 0.72 \pm 0.18 \pm 0.10$. In addition, we report the combined ARGUS results on $\rho$, $\xi$, and $\xi\delta$ using this work und previous measurements.Comment: 10 pages, well formatted postscript can be found at http://pktw06.phy.tu-dresden.de/iktp/pub/desy97-194.p

Socio-Informatics

Contents Editorial Thematic Focus: Socio-Informatics Introduction to the Thematic Focus “Socio-Informatics” / Claudia Müller Digitalisation in Small German Metal-Working Companies. Appropriation of Technology in a “Traditional” Industrial Domain / Bernhard Nett, Jennifer Bönsch Travelling by Taxi Brousse in Madagascar: An Investigation into Practices of Overland Transportation / Volker Wulf, Kaoru Misaki, Dave Randall, and Markus Rohde Mobile and Interactive Media in the Store? Design Case Study on Bluetooth Beacon Concepts for Food Retail / Christian Reuter, Inken Leopold Facebook and the Mass Media in Tunisia / Konstantin Aal, Marén Schorch, Esma Ben Hadj Elkilani, Volker Wulf Book Review Symposium Charles Goodwin Charles Goodwin’s Co-Operative Action: The Idea and the Argument / Erhard Schüttpelz, Christian Meyer Multi-Modal Interaction and Tool-Making: Goodwin’s Intuition / Christian Meyer, Erhard Schüttpelz Co-Operation is a Feature of Sociality, not an Attribute of People : “We inhabit each other’s actions.” (Goodwin, cover) / Jutta Wiesemann, Klaus Amann The Making of the World in Co-Operative Action. From Sentence Construction to Cultural Evolution / Jürgen Streeck On Goodwin and his Co-Operative Action / Jörg R. Bergman