Directly measuring the neutrino mass: the MIBETA 187Re single-beta decay experiment

par Alessandro Monfardini

lundi 3 avr. 2006, 14:00 → 15:00 Europe/Paris

Amphithéâtre

Unlike double-beta decay, classical beta endpoint measurements search for a kinematic effect induced by the neutrino mass. This technique, which is essentially free of theoretical assumptions about neutrino properties, represents the only genuine "direct" approach to the problem of measuring the absolute value of m_nu. So far, the most stringent direct limits (m_nu < 2.2eV) have been obtained by means of electrostatic spectrometers and 3H sources. A huge, new generation spectrometer (KATRIN) will become operational in 2010. We present an alternative and potentially competitive micro-approach based on 187Re beta-decay and cryogenic detectors. A first limit of 15eV has been achieved in 2003 with a pilot, small array of eight micro-bolometers. I present the first run results and the ongoing technological developments for the 2nd phase of the experiment (200 channels). Moreover, I will briefly describe the proposed MARE (Microcalorimeters Arrays for a Rhenium Experiment) to break into the sub-eV range. Interesting by-products with implications in Nuclear and Solid State Physics will be described (e.g. Beta Environment Fine Structure) together with the efforts for understanding other possible systematic effects.

Slides monfardini.pdf