Why is measuring the neutrino's mass so extraordinarily difficult?
Trillions of neutrinos pass through your body every second, yet we still can't pin down how much they weigh.
The answer
Neutrinos are the lightest known massive particles, and measuring their mass remains one of physics' greatest challenges. The KATRIN experiment in Karlsruhe, Germany, directly measures the electron antineutrino mass by analyzing the energy spectrum of tritium beta decay. In 2024, KATRIN set the upper limit at 0.45 electron volts (eV) - less than one-millionth the mass of an electron. Cosmological observations from the Planck satellite constrain the sum of all three neutrino masses to below 0.12 eV. The upcoming Project 8 experiment aims to reach 0.04 eV sensitivity using cyclotron radiation emission spectroscopy. Knowing neutrino masses precisely would reveal whether they are their own antiparticles and help explain matter-antimatter asymmetry.
Source: KATRIN Experiment
- neutrinos
- particle physics
- KATRIN
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