The mystery of neutrino mass could soon be solved

[eppur_se_muova]

3. Sounds like they're doing (Fermi-) Kurie plots, using more accurate data from a new detector ...

... but I could be wrong.

Kurie plot

A Kurie plot (also known as a Fermi–Kurie plot) is a graph used in studying beta decay developed by Franz N. D. Kurie, in which the square root of the number of beta particles whose momenta (or energy) lie within a certain narrow range, divided by the Fermi function, is plotted against beta-particle energy.[34][35] It is a straight line for allowed transitions and some forbidden transitions, in accord with the Fermi beta-decay theory. The energy-axis (x-axis) intercept of a Kurie plot corresponds to the maximum energy imparted to the electron/positron (the decay's Q value). With a Kurie plot one can find the limit on the effective mass of a neutrino.[36]

https://en.m.wikipedia.org/wiki/Beta_decay#Kurie_plot

"Ordinary" double beta decay results in the emission of two electrons and two antineutrinos. If neutrinos are Majorana particles (i.e., they are their own antiparticles), then a decay known as neutrinoless double beta decay will occur. Most neutrino physicists believe that neutrinoless double beta decay has never been observed.[43]

https://en.m.wikipedia.org/wiki/Beta_decay#Double_beta_decay