Status and prospects of searches for neutrinoless double beta decay

The simultaneous beta decay of two neutrons in a nucleus without the emission of neutrinos (called neutrinoless double beta decay) is a lepton number violating process which is not allowed in the Standard Model of particle physics. More than a dozen experiments using different candidate isotopes and a variety of detection techniques are searching for this decay. Some (EXO-200, Kamland-Zen, GERDA) started to take data recently. EXO and Kamland-Zen have reported first limits of the half life $T_{1/2}^{0\nu}$ for $^{136}$Xe. After a decade of little progress in this field, many new results will soon scrutinize the claim from part of the Heidelberg-Moscow collaboration to have observed this decay. The sensitivities of the different proposals are reviewed.Comment: 15 pages, 3 figures, submitted to Annalen der Physik (Berlin

Neue Heimat in Westfalen?:Zuzug von Migranten nach Dorsten – Wulfen zwischen 1960 und 2010

Die Arbeit erforscht die Zuwanderung von Migranten nach Dorsten-Wulfen seit 1960. Dabei werden statistisch sichtbare „Zuwanderungswellen“ von den britischen Soldaten über „Gastarbeiter“-Migranten und vietnamesische Boat People bis hin zu Aussiedlern aus der ehemaligen Sowjetunion vorgestellt. Anhand von Interviews mit Auswanderern und verschiedensten Archivmaterialien wird die Frage untersucht, warum diese Menschen ihre Heimat verlassen und sich in Dorsten-Wulfen niedergelassen haben, und ob die Fremde zur neuen Heimat geworden ist. Am Beispiel dieses Dorstener Ortsteils wird so die Migrationsgeschichte der BRD insgesamt mit ihren Auswirkungen auf Einheimische und Zugezogene erzählt

Pulse shape discrimination performance of Inverted Coaxial Ge detectors

We report on the characterization of two inverted coaxial Ge detectors in the context of being employed in future $^{76}$Ge neutrinoless double beta ($0\nu\beta\beta$) decay experiments. It is an advantage that such detectors can be produced with bigger Ge mass as compared to the planar Broad Energy Ge detectors (BEGe) that are currently used in the GERDA $0\nu\beta\beta$ decay experiment. This will result in lower background for the search of $0\nu\beta\beta$ decay due to a reduction of cables, electronics and holders. The measured resolution near the $^{76}$Ge Q-value at 2039 keV is 2.5 keV and their pulse-shape characteristics are similar to BEGe-detectors. It is concluded that this type of Ge-detector is suitable for usage in $^{76}$Ge $0\nu\beta\beta$ decay experiments

Deinterlacing und zeitliche Skalierung im Umfeld der UHD Konvertierung

Diese Arbeit untersucht die zeitliche Interpolation von Videosignalen. Durch die Einführung des Ultra High Definition Television Standard wird eine höhere Bildwiederholrate benötigz um Judder-Artefakte zu vermeiden. In diesem Zusammenhang kommt der zeitlichen Interpolation von nicht nativem UHD Material eine besondere Bedeutung zu. Neben der räumlichen Interpolation ist diese essenziell. In dieser Arbeit wird eine Übersicht über die Anforderungen an UHD Video gegeben. Bewegungskompensierende Verfahren für das Deinterlacing und Upscaling in Verbindung mit einer Phasenkorrelation werden behandelt. Ein MATLAB-Programm wird entwickelt mit dem ein Upscaling und Deinterlacing von HD Material durchgeführt werden kann

Development and test results of a readout chip for the GERDA experiment

This paper describes the F-CSA104 architecture and its measurement results. The F-CSA104 is for γ spectroscopy with Ge detectors. It is a low noise, fully integrated, four channel XFAB 0.6μm CMOS technology ASIC, that has been developed for the GERDA experiment. Each channel contains a charge sensitive preamplifier (CSA) followed by a 11.7MHz differential line driver. It has been particularly designed to operate in liquid argon (T = 87K/-186°C) and to have a measuring sensitivity of 660e- with an ENC of 110e-, after offline filtering with 10μs shaping, when connected to a 30pF load. Special techniques are used to improve the SNR such as a large input PMOS FET, an integrated 500MΩ CSA feedback resistor and a noise degeneration drain resistor

No CPT Violation from Tilted Brane in Neutral Meson--Antimeson Systems

Tilted brane in theories with large compact extra dimensions leads to spontaneous symmetry breaking of the Lorentz and rotational invariance in four dimensions, as shown by Dvali and Shifman. In this brief report, we point out that the mentioned Lorentz symmetry breaking, although leading to the CPT--violating interaction terms, cannot lead to the CPT violation in the experimentally interesting $K$--${\bar K}$ and analogous systems.Comment: 5 pages, RevTe

Possible Spontaneous Breaking of Lorentz and CPT Symmetry

One possible ramification of unified theories of nature such as string theory that may underlie the conventional standard model is the possible spontaneous breakdown of Lorentz and CPT symmetry. In this talk, the formalism for inclusion of such effects into a low-energy effective field theory is presented. An extension of the standard model that includes Lorentz- and CPT-breaking terms is developed. The restriction of the standard model extension to the QED sector is then discussed.Comment: Talk presented at Non-Accelerator New Physics, Dubna, Russia, July 199