Operational Quantum Mechanics, Quantum Axiomatics and Quantum Structures

The role of operational quantum mechanics, quantum axiomatics and quantum structures in general is presented as a contribution to a compendium on quantum physics, its history and philosophy.Comment: 6 page

Konjunktur 2007

Das HWWI hat für die Jahre 2007 und 2008 eine neue Prognose der wirtschaftlichen Entwicklung erstellt. Demnach wächst das Bruttoinlandsprodukt in 2007 um 1,7 Prozent und im Jahr 2008 um 2 Prozent. Die Mehrwertsteuererhöhung wird zu einer spürbaren Verlangsamung des Wachstums führen. Gleichwohl wird die Konjunktur 2007 deutlich aufwärts gerichtet bleiben. Dazu trägt nicht zuletzt die steigende Beschäftigung bei. Die Zahl der Arbeitslosen wird 2007 um 380 000 zurückgehen. Die Konsolidierungspolitik führt zu einer weiteren Abnahme des Budgetdefizits auf 1,3 Prozent des nominalen Bruttoinlandsprodukts. --

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements