Particle physics: neutrinos are more difficult to explain than expected

If the model of neutrinos correctly determines their original energies, it should also provide suitable values ​​for electrons after careful calculations. The researchers took data from an experiment in which electron beams of different energies were systematically fired at atomic nuclei at Jefferson Laboratory in the US state of Virginia, and the resulting particles were measured comprehensively. Here were the nuclei of interest, helium, carbon and iron, which can be compared with the target objects in different neutrino detectors. The chosen electron energies are also consistent with energies of typical neutrino experiments. In addition, physicists limited their analysis to events that were easy to explain in order to reduce potential sources of error.

Despite the considerable effort, the result was realistic: the models performed poorly at delivering the correct energies of electron beams within a five percent tolerance range. Overall, this was achieved in less than half of the events, in the case of carbon nuclei only in about a third of all cases, and in the case of iron barely a quarter.

It is clear that the theoretical understanding of neutrino interactions is expandable even in areas that appear to have been well covered thus far. The exact reasons for the discrepancy must now be understood in order for the models to be more reliable. This is important at the moment, the team stresses in light of their planned investigation campaigns with large-scale systems under construction: “Now that we have entered an era of precise measurements on neutrinos, it will be necessary to make models accurate and reliable.” The better the raw data from the instruments. For future detection, the importance of removing inaccuracies in models for its evaluation has increased. Otherwise, the desired resolution disappears under thick error bands and unnecessarily leaves many already-fuzzy neutrinos in the dark.