Bochum 1998 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
HK: Hadronen und Kerne
HK 29: Weak Interactions and Fundamental Symmetries II
HK 29.3: Talk
Tuesday, March 17, 1998, 14:45–15:00, E
New Results from the Mainz Neutrino Mass Experiment — •B. Degen, H. Barth, A. Bleile, J. Bonn, L. Bornschein, L. Fleischmann, E. Otten, M. Przyrembel, and Ch. Weinheimer — Institut für Physik, Joh. Gutenberg-Universität, 55099 Mainz
First measurements of the shape of the β spectrum of molecular tritium with the upgraded Mainz Solenoid Retarding Spectrometer [1,2] are reported. The signal to background ratio could be improved by a factor of 10 compared to data taking in 1994 by increasing the source strength by a factor of 6 and simultaneously decreasing the background by 40%. High statistics measurements of the tritium spectrum very close to the endpoint and measurements on systematics have been performed. The excellent signal to background ratio enables us to derive information on the mass of the electron antineutrino from the extreme high energy end of the β spectrum, where the influence of the neutrino mass is at maximum and most of the systematic uncertainties vanish. According to a preliminary evaluation this measurement has a sensitivity limit for the mass of the electron antineutrino of about 4 eV/c2. Additional measurements of the tritium spectrum and of the energy loss in the source are under way. Results and the current status and perspectives of the experiment will be given.
Supported by the Deutsche Forschungsgemeinschaft.
[1] A. Picard et al., Nucl. Instr. Meth. B63, 345 (1992)
[2] L. Bornschein, contribution to this meeting