Thursday, March 19, 2015, 16:00
WHGA/Auditorium
Christian Weinheimer, University of Münster
Abstract:
Since the discovery of neutrino oscillation we know that neutrinos have non-zero masses, but we do not know the absolute neutrino mass scale, which is very important for cosmology as well as for particle physics. The direct search for a non-zero neutrino mass from endpoint spectra of weak decays is complementary to the search for neutrinoless double beta-decay and analyses of cosmological data
and does not request further assumptions. It only requires energy and momentum conservation and applies the relativistic energy-momentum relationship. The most stringent limits on the neutrino mass originate from investigations of the electron energy spectra of tritium beta-decay.
Currently the Karlsruhe Tritium Neutrino experiment KATRIN is under construction and commissioning. It will improve the best limit from the tritium beta decay experiments at Mainz and Troitsk of 2 eV by one order of magnitude probing the region relevant for structure formation in the universe. KATRIN uses a strong windowless gaseous molecular tritium source combined with a huge MAC-E-Filter as electron spectrometer. Data from the two commissioning phases of the spectrometer and detector section will be presented.
In addition to a report on the KATRIN experiment an outlook on up-coming new approaches to the neutrino mass, like bolometric experiments using the electron capture of Ho-163, will be given.