Two old ways to measure the electron-neutrino mass

Understand

Three decades ago, the measurement of the electron neutrino mass in atomic electron capture (EC) experiments was scrutinized in its two variants: single EC and neutrino-less double EC.

• For certain isotopes an atomic resonance enormously enhances the expected decay rates.
• The favoured technique, based on calorimeters as opposed to spectrometers, has the advantage of greatly simplifying the theoretical analysis of the data.
• After an initial surge of measurements, the EC approach did not seem to be competitive.