Have you ever wondered about the weight of a resting neutrino? This intriguing question remains unanswered in the realm of physics. Neutrinos, those mysterious particles, hold a significant role in the natural world. Klaus Blaum, leading a team at the Max Planck Institute for Nuclear Physics in Heidelberg, has made a remarkable stride in measuring the weight of neutrinos as part of the global ECHo collaboration. Their groundbreaking discoveries have been unveiled in the prestigious pages of Nature Physics.
Back in the 1930s, the radioactive beta decay of an atomic nucleus revealed a discrepancy in energy and momentum balance. This anomaly led to the hypothesis of ”ghost particles” that discreetly carry away energy and momentum. It wasn’t until 1956 that experimental evidence of these elusive neutrinos was finally confirmed. The enigma lies in the fact that neutrinos only interact with other particles through the weak interaction, the same force driving the beta decay of atomic nuclei.
Every second, our bodies are traversed by countless neutrinos from the cosmos, particularly from the sun, without causing any harm. Detecting these rare collisions of neutrinos with other particles requires colossal detectors.
The revelation from solar neutrinos was groundbreaking: the three known types of neutrinos can morph into one another. This phenomenon, known as “neutrino oscillations,” had profound implications for the field of particle physics. Previously, it was believed that neutrinos, like photons, had no resting mass.
This notion aligned with the standard model of particle physics, the most comprehensive framework of the particle universe. However, the discovery of neutrino oscillations necessitated a resting mass for neutrinos, hinting at the existence of new physics beyond the standard model.
2024-04-20 03:51:01
Source from phys.org