What are Neutrinos?
- Neutrinos are electrically neutral subatomic particles that are produced in processes like radioactive decay and nuclear reactions, including those occurring in the sun and stars.
- They are one of the fundamental particles in the Standard Model of particle physics, but their mass remains unknown.
- Unlike other fundamental particles, neutrinos are extremely lightweight, with masses less than a millionth that of an electron.
What is the KATRIN Experiment?
- KATRIN stands for Karlsruhe Tritium Neutrino experiment, and it is located in Karlsruhe, Germany.
- Its primary aim is to precisely measure the mass of the electron antineutrino, a type of neutrino produced in beta decay.
- The experiment focuses on studying the decay of tritium, a radioactive isotope of hydrogen, which emits both an electron and an electron antineutrino.
- The energy of the emitted electron is affected by the mass of the neutrino — hence, measuring electron energies helps infer the upper limit of the neutrino’s mass.
Recent Findings
- In its latest analysis, KATRIN has reduced the upper limit of the neutrino mass to less than 0.45 electron volts (eV).
- This is a significant improvement over its earlier result and represents a nearly 50% reduction in the previously estimated maximum value.
- The data is based on the precise measurement of energies from 36 million electrons produced in tritium decay.
