Relativistic Cyclotron Radiation Detection of Tritium Decay Electrons as a New Technique for Measuring the Neutrino Mass

Understand

The shape of the beta decay energy distribution is sensitive to the mass of the electron neutrino.

• Attempts to measure the endpoint shape of tritium decay have so far seen no distortion from the zero-mass form, thus placing an upper limit of m_nu_beta < 2.3 eV.
• Here we show that a new type of electron energy spectroscopy could improve future measurements of this spectrum and therefore of the neutrino mass.
• We propose to detect the coherent cyclotron radiation emitted by an energetic electron in a magnetic field.