How heavy are neutrinos? To find out, radioactive decays are studied in which they are emitted. An essential ingredient is the decay energy which corresponds to the mass difference between the mother and daughter nuclei. It must be known with highest precision. A team of scientists now succeeded to resolve a severe discrepancy of the decay energy for the artificial holmium (Ho) isotope with mass number 163. It decays by electron capture to the stable dysprosium-163 (163Dy) and appears well suited to measure the neutrino mass. The team prepared pure samples of 163Ho and 163Dy and directly measured their mass difference with high accuracy using the Penning-trap mass spectrometer SHIPTRAP.
How heavy are neutrinos? To find out, radioactive decays are studied in which they are emitted. An essential ingredient is the decay energy which corresponds to the mass difference between the mother and daughter nuclei. It must be known with highest precision. A team of scientists now succeeded to resolve a severe discrepancy of the decay energy for the artificial holmium (Ho) isotope with mass number 163. It decays by electron capture to the stable dysprosium-163 (163Dy) and appears well suited to measure the neutrino mass. The team prepared pure samples of 163Ho and 163Dy and directly measured their mass difference with high accuracy using the Penning-trap mass spectrometer SHIPTRAP.