It is also extremely tiny-approximately 500,000 times smaller than an electron. They found its upper limited to be 1.1 electronvolts, approximately half of the previously determined upper limit. By measuring the energy of the released electron using the spectrometer, they were able to calculate an estimate of the mass of the neutrino to a greater precision than was possible before. When it decays, it emits a single electron and a neutrino at the same time. The researchers used it to study the decay of tritium-a radioactive type of hydrogen. The core piece of equipment used at the site is a 200-ton electron spectrometer. The researchers carried out their work as part of the Karlsruhe Tritium Neutrino Experiment ( KATRIN) on the campus of the Karlsruhe Institute of Technology in Germany. In this new effort, the researchers have taken the third approach. The third method involves attempting to measure the mass of the neutrino directly in ways that do not rely on a theoretical model. The second involves carrying out searches for instances of neutrinoless double-beta decay-an extremely rare event. Neutrinos in High-Energy Physics and Astrophysics. Upper limits are listed as about0.01, 0.5, and 40 electron masses, respectively, for the electron, muon, and tau types of neutrinos. It is now thought that neutrinos have mass, but the masses are not well determined. The first involves studying the cosmic microwave background. The mass of the electron neutrino is very small and was for a long time believed to be zero. To date, scientists have taken three approaches to finding the answer. The next step is to determine their mass. But recent studies have found that not to be the case. One property of the neutrino in particular that scientists would like to nail down is its mass-until recently, it was thought the tiny particles had no mass at all. Many also believe they hold the key to understanding the early universe, and perhaps physics at its smallest level. They would like to know more about the particles because they are so abundant-scientists believe there are 1 billion times more of them in the universe than atoms.
![electron neutrino mass electron neutrino mass](https://media.proprofs.com/images/discuss/user_images/153336/6978312292.jpg)
Neutrinos are mysterious-scientists have found evidence of their existence, but are still struggling to understand their properties.