What are neutrinos? Where are they found?

Question

What are neutrinos?  Where are they found?

Piper Hoffman · Accepted Answer

Neutrinos are small neutral particles weakly interacting particle with very little mass. They are classified as leptons a subgroup of fermions. There are three "flavours" of neutrinos, electron, muon and tau neutrinos, each of these flavours has a particle and an antiparticle, so there are six kinds of neutrinos in total.

Neutrinos are everywhere, following through you me, the earth, but they don't interact much. The best place in the solar system to look for neutrinos is flowing out of the sun as they are created by nuclear fusion processes in its core.

Neutrinos are tiny, massless, neutral particles that flow through everyone and everything, including you and the earth, but they interact very little. There are three "flavors" of neutrinos: electron, muon, and tau neutrinos. Each of these flavors has a particle and an antiparticle, making a total of six different types of neutrinos. They are categorized as leptons, a subgroup of fermions. The following symbols correspond to the six neutrinos (based on the small Greek letter "nu") #nu_{e}# electron neutrino lepton number 1 #bar{nu}_{e}# anti-electron neutrino lepton number -1 #nu_{mu}# muon neutrino lepton number 1 #bar{nu}_{mu}# anti-muon neutrino lepton number -1 #nu_{tau}# tau neutrino lepton number 1 #bar{nu}_{tau}# anti-tau neutrino lepton number -1 Since neutrinos are neutral leptons, their only means of interaction are gravity and the weak force. Relationships Gravity: Although neutrinos are affected by gravity, the effect is minimal due to their small mass. Because lepton number is conserved, neutrinos appear and disappear when an electron (or muon or tau particle) does. Neutrinos occur in beta decay and related processes, some fission and fusion reactions, and scatter with electrons (theoretically muons and tau particles too). Weak: This is the main way material effects neutrinos in the standard model. This means that neutrinos are involved in certain nuclear reactions. The neutrino was discovered when it was realized that momentum was not conversed in beta decay (as measured at the time); seeing a neutron break up into an electron and a proton, it was realized there was another small neutral particle not accounted for. The name "neutrino" basically means "little neutral one." These particles are most commonly associated with beta decay, where a neutron decays into a proton, an electron, and... a neutrino. Not Interacting The electromagnetic force does not affect them, so they are not drawn to or repellent from charged particles, they do not directly interact with magnetic fields, and photons, or light, have no effect on them. Strong: They are not bonded to the nucleus because they are not affected by the strong nuclear force. Together, these indicate that if an atom experiences a weak interaction that produces a neutrino, it will easily escape the atom. Solar neutrino problem and oscillations of mass and matter. Three nuclear reactions take place in the sun's core that result in the production of neutrinos, the most common of which is the proton-proton reaction that initiates fusion. #p^{+} + p^{+} -> d^{+} + e^{-} + nu_e # We could quantify nuclear fusion in the sun by counting neutrinos and measuring electron neutrinos! It was discovered that neutrinos had mass and that this allowed them to switch flavor, with some electron neutrinos becoming muon or tau neutrinos when they passed through matter (leaving the sun or passing through the earth), so we found the missing neutrinos. However, we only found 1/3 of the expected number of neutrinos!

Joseph Allen · Answer

undefined Throughout the universe, neutrinos—subatomic particles with an incredibly small mass and no electric charge—are produced in nuclear reactors and particle accelerators and can be found in the core of stars, during nuclear reactions, supernovae explosions, and interactions between cosmic rays and Earth's atmosphere.