phys.org -:NEUTRINO:Neutrinos are produced from radiation, so it might be possible for the International Atomic Energy Agency to use neutrino detectors to monitor which countries are following the treaty on the Non-Proliferation of Nuclear Weapons. ... U.S. Department of Energy In most nuclear reactors, uranium decays into plutonium. Mar 1, 2014 The mass of the neutrino : 0.320 ± 0.081 eV/c² Symbol: v̅e, ντ, v̅μ, v̅τ, νμ, νe Discoverer: Frederick Reines, Clyde Cowan, Leon M. Lederman, Jack Steinberger, Melvin Schwartz. Interactions: Gravity, Weak interaction Composition: Elementary particle Neutrino/Antineutrino The first use of a hydrogen bubble chamber to detect neutrinos, on 13 November 1970, at Argonne National Laboratory. Here a neutrino hits a proton in a hydrogen atom; the collision occurs at the point where three tracks emanate on the right of the photograph. Composition Elementary particle Statistics Fermionic
Generation First, second and third Interactions Weak interaction and gravitation Symbol ν , e ν , μ ν , τ ν , e ν , μ ν τ Antiparticle Theorized Opposite chirality from particle • ν (Electron neutrino): Wolfgang Pauli (1930) e • ν (Muon neutrino): Late 1940s μ • ν (Tau neutrino): Mid 1970s τ Discovered • ν : Clyde Cowan, Frederick Reines (1956) e • ν : Leon Lederman, Melvin Schwartz and Jack μ
Steinberger (1962) • ν : DONUT collaboration(2000) τ Types 3 – electron neutrino, muon neutrino and tau neutrino Mass ≤ 0.120 eV/c2 (95% confidence level, sum of 3 flavors) Electric charge 0e Spin ½ Weak isospin LH: +1/2, RH: 0 Weak hypercharge LH: −1, RH: 0 B−L −1 X −3 A neutrino (/nuːˈtriːnoʊ/ or /njuːˈtriːnoʊ/) (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. The mass of the neutrino is much smaller than that of the other known elementary particles. 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 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. The weak force has a very short range, the gravitational interaction is extremely weak, and neutrinos, as leptons, do not participate in the strong interaction. Thus, neutrinos typically pass through normal matter unimpeded and undetected. Antineutrinos: For each neutrino, there also exists a corresponding antiparticle, called an antineutrino, which also has no electric charge and half-integer spin. They are distinguished from the neutrinos by having opposite signs of lepton number and opposite chirality. As of 2016, no evidence has been found for any other difference. In all observations so far of leptonic processes (despite extensive and continuing searches for exceptions), there is no overall change in lepton number; for example, if total lepton number is zero in the initial state, electron neutrinos appear in the final state together with only positrons (anti-electrons) or electron-antineutrinos, and electron antineutrinos with electrons or electron neutrinos.  Antineutrinos are produced in nuclear beta decay together with a beta particle, in which, e.g., a neutron decays into a proton, electron, and antineutrino. All antineutrinos observed thus far possess right-handed helicity (i.e. only one of the two possible spin states has ever been seen), while neutrinos are left-handed. Nevertheless, as neutrinos have mass, their helicity is frame-dependent, so it is the related frame-independent property of chirality that is relevant here. Antineutrinos were first detected as a result of their interaction with protons in a large tank of water. This was installed next to a nuclear reactor as a controllable source of the antineutrinos (See: Cowan–Reines neutrino experiment). Researchers around the world have begun to investigate the possibility of using antineutrinos for reactor monitoring in the context of preventing the proliferation of nuclear weapons.