MLL-Kolloquium: Prof. Stefan Schönert (TU München / Physik Department E15) : Search for neutrinoless double beta decay of Ge-76 with the GERmanium Detector Array GERDA: Results from the commissioning phase

Thursday 14 Jul 2011, 16:00 → 17:00 Europe/Berlin

LMU Building, Am Coulombwall 1, Garching, Lecture Hall (ground floor)

The study of neutrino-less double beta decay (DBD) is the most powerful approach to the fundamental question if the neutrino is a Majorana particle, i.e. its own anti-particle. The observation of neutrinoless DBD would not only establish the Majorana nature of the neutrino but also represent a measurement of its effective mass. So far, the most sensitive results have been obtained with Ge-76, and the group of Klapdor-Kleingrothaus has made a claim of discovery. Future experiments have to reduce radioactive backgrounds to increase sensitivity. GERDA is a new double beta-decay experiment which is currently in its commissioning phase in the INFN Gran Sasso National Laboratory, Italy. It is implementing a new shielding concept by operating bare Ge diodes - enriched in Ge-76 - in high purity liquid argon supplemented by a water shield. The aim of GERDA is to verify or refute the recent claim of discovery, and, in a second phase, to achieve a two orders of magnitude lower background index than recent experiments. The talk will discuss design, physics reach, and report about the status of the commissioning of GERDA, and present results from the R&D on novel background reduction methods using novel HP-Ge detectors with small read-out electrodes and liquid argon instrumentation.

Abstract kolloquium-14-07-11.pdf