Juan José Hernández Rey
Research professor at the Spanish National Research Council (CSIC) at the Institute of Corpuscular Physics (IFIC) in Valencia (University of Valencia-CSIC), co-principal investigator of the KM3NeT research team at IFIC and co-leader of the VEGA Group at IFIC
The new result of the KATRIN collaboration further limits the mass of neutrinos. It is a very solid result, both because of the careful analysis of the experimental data and because of the method used, namely the analysis of the energy spectrum in the disintegration of tritium, which requires very few auxiliary hypotheses. It is likely that KATRIN will approach 0.3 eV sensitivity by the end of 2025 but, unfortunately, that will be the limit of its reach.
The significance of the result may seem relative, as the combined data from different cosmological experiments seem to indicate that the sum of the neutrino masses has to be at least almost ten times lower (0.05 eV), but the method used by KATRIN is much more direct and ‘less model dependent’, in the jargon of physicists.
Knowing the exact mass of neutrinos will give us new clues as to what theory lies beyond the Standard Model of Particle Physics. Thus, for example, a hypothesis known as the seesaw mechanism directly links their minuscule mass with very high-energy physical phenomena, which makes neutrinos a gateway to the long-awaited ‘New Physics’.