A new route for neutrino mass determination using the electron capture of 194Hg

The electron neutrino mass is of highest importance for many fields of physics. To measure the neutrino mass, beta-decay spectra are typically used. Here an alternative way to determine the neutrino mass, using an electron capture in 194Hg will be presented. Direct mass measurements of 194Hg and its daughter nucleus 194Au were performed at the high-precision Penning trap mass spectrometer ISOLTRAP at the ISOLDE facility (CERN). The QEC-value obtained by the mass difference of these nuclei leads to the conclusion that the K-capture is forbidden, thus an L-capture is assumed. For further investigations a measurement using a cryogenic micro-calorimeter is suggested. From this, a de-excitation spectrum is obtained which can be compared to the QEC-value in order to determine the neutrino mass.