![]() ![]() Thus, neutrinos typically pass through normal matter unimpeded and undetected. The weak force has a very short range, gravity is extremely weak on the subatomic scale, and neutrinos, as leptons, do not participate in the strong interaction. The neutrino is so named because it is electrically neutral and because its rest mass is so small (-ino) that it was long thought to be zero. Although only differences of squares of the three mass values are known as of 2016, cosmological observations imply that the sum of the three masses must be less than one millionth that of the electron. The mass of the neutrino is much smaller than that of the other known elementary particles. About 30 neutrinos are detected per day.A neutrino ( or ) (denoted by the Greek letter ν) is a fermion (an elementary particle with half-integer spin) that interacts only via the weak subatomic force and gravity. For example, at the Sudbury Neutrino Observatory, a solar-neutrino detector with 1000 tonnes of heavy water raises about 1012 neutrinos. As a result, all terrestrial neutrinos experiments rely on measuring a small fraction of neutrinos that interact with detectors of appropriate size. Typically, low-energy neutrinos undergo several mild-to-normal cases before interacting with anything. To detect neutrinos, very large and very sensitive detectors are required. How to detect neutrinos? (How to find neutrinos?) Other neutrinos are produced by frequent nuclear power stations, particle accelerators, atomic bombs, normal atmospheric phenomena, star births, collisions, and deaths, especially supernova explosions. Theoretically, there are now so many neutrinos that they constitute cosmic background radiation with a temperature of 1.9 ° Kelvin (-271.2 ° C). Since this time, the universe has steadily expanded and cooled, and neutrinos have just kept moving. Where do Neutrinos come from and where are they found?Īccording to what we know about neutrinos today, most neutrinos were born about 15 billion years ago, soon after the birth of the universe. By this fact leptons (leptons are elementary particles of half-integer spin that do not undergo strong interactions.) Are divided into three categories, each with a charged lepton and its accompanying neutrino. The three neutrino types appear to be different: for example, when muon-neutrino interacts with a target, they will always produce muon, and never tau or electrons.Īlthough electrons and electron-neutrinos can be created and destroyed in particle interactions, the sum of the number of electrons and electron-neutrinos is preserved. Like electrons, both muon and tau are accompanied by neutrinos, which are called muon-neutrino and tau-neutrino. Their unique advantage arises from a fundamental property: they are affected only by the weakest of the forces of nature (but for gravity) and are therefore essentially detached as they travel the cosmic distance between their origin and ours. ![]() Produced significantly in high-energy collisions, traveling essentially at the speed of light, and unaffected by magnetic fields, Neutrino fulfills the basic requirements for astronomy. There are three different types of Neutrino, each related to a charged particle as shown in the following table. ![]() Of all high-energy particles, only weakly interacting with Neutrino can directly convey astronomical information from the edge of the universe - and as far as we know, within the most catastrophic high-energy processes. ![]() Neutrino was named by Enrico Fermi as a wordplay on neutron, which is the Italian name for neutron. ![]()
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