why do neutrinos exist?

Question

why do neutrinos exist?

Answer 1

Neutrinos exist because Quantum physics demands they exist. In the decay of a Neutron into an Electron and Proton some extra enegry had to be expelled. Thus Quantum physics created the Neutrinos.



The neutrino was first postulated in December, 1930 by Wolfgang Pauli to explain the energy spectrum of beta decays, the decay of a neutron into a proton and an electron. Pauli theorized that an undetected particle was carrying away the observed difference between the energy and angular momentum of the initial and final particles. Because of their "ghostly" properties, the first experimental detection of neutrinos had to wait until about 25 years after they were first discussed. In 1956 Clyde Cowan, Frederick Reines, F. B. Harrison, H. W. Kruse, and A. D. McGuire published the article "Detection of the Free Neutrino: a Confirmation" in Science (see neutrino experiment), a result that was rewarded with the 1995 Nobel Prize.



The name neutrino was coined by Enrico Fermi - who developed the first theory describing neutrino interactions - as a word play on neutrone, the Italian name of the neutron. (Neutrone in Italian means big and neutral, and neutrino means small and neutral.)



In 1962 Leon M. Lederman, Melvin Schwartz and Jack Steinberger showed that more than one type of neutrino exists by first detecting interactions of the muon neutrino. When a third type of lepton, the tau, was discovered in 1975 at the Stanford Linear Accelerator, it too was expected to have an associated neutrino. First evidence for this third neutrino type came from the observation of missing energy and momentum in tau decays analogous to the beta decay that had led to the discovery of the neutrino in the first place. The first detection of actual tau neutrino interactions was announced in summer of 2000 by the DONUT collaboration at Fermilab, making it the latest particle of the Standard Model to have been directly observed.



A practical method for investigating neutrino masses (that is, flavour oscillation) was first suggested by Bruno Pontecorvo in 1957 using an analogy with the neutral kaon system; over the subsequent 10 years he developed the mathematical formalism and the modern formulation of vacuum oscillations. In 1985 Stanislav Mikheyev and Alexei Smirnov (expanding on 1978 work by Lincoln Wolfenstein) noted that flavour oscillations can be modified when neutrinos propagate through matter. This so-called MSW effect is important to understand neutrinos emitted by the Sun, which pass through its dense atmosphere on their way to detectors on Earth.

Answer 2

In certain radioactive decays there was not a conservation between energy and momentum. This was explained by a particle called a neutrino that carried off some of the energy.

If the neutrino did not exist, then the extra radiation would not allow chemical bonding to be as strong as it is.

Another point is that the neutrino as best as we can describe is a neutral electron. Just as there are positrons to the electrons, it makes sense that somewhere in the universe, a neutral electron exists.

Answer 3

Neutrinos exist due to the CP conservation laws (not energy and momentum conservation as has been stated so far, these can be conserved without the need of neutrinos).

The C is charge, that it is conserved is obvious.

The P is parity, or handedness (left or right). It is like the quantum analogue of angular momentum conservation (or conservation of spinnyness).

In beta minus decay when a neutron decays into a proton an electron is also given off in order to conserve charge. The neutron, proton and electron are all spin +/- 1/2 particles so we need another spin +/- 1/2 particle in order to be able to balance the spins on both sides of the equation. This spin +/- 1/2 particle is the neutrino (antineutrino in this case).

Answer 4

Cannot be answered. We do not know why any particles exist, they just do. We are still studying them.



But if you are asking how a neutrino comes about, that is a different story.



In beta decay Carbon 14 decays to Nitrogen 14, and electron and a neutrino. This happens when one of the neutrons in the carbon decays in a proton, electron, and neutrino.

Answer 5

In 1956 Clyde Cowan, Frederick Reines, F. B. Harrison, H. W. Kruse, and A. D. McGuire printed the item "Detection of the unfastened Neutrino: a confirmation" in technology, a effect that became into rewarded with the 1995 Nobel Prize. in this test, now accepted using fact the neutrino test, neutrinos created in a nuclear reactor by potential of beta decay have been shot into protons generating neutrons and positrons the two one in all that is detected. We now comprehend that the two the proposed and the reported debris have been antineutrinos. Nuclear reactors are the main significant source of human-generated neutrinos. Anti-neutrinos are made interior the beta-decay of neutron-rich daughter fragments interior the fission technique. commonly, the 4 important isotopes contributing to the anti-neutrino flux are: uranium-235, uranium-238, plutonium-239 and plutonium-241. an accepted nuclear means plant would generate over 1020 anti-neutrinos in step with 2d. some particle accelerators have been used to make neutrino beams. The technique is to smash protons right into a fastened aim, generating charged pions or kaons. those risky debris are then magnetically centred right into an prolonged tunnel the place they decay collectively as in flight. using relativistic enhance of the decaying particle the neutrinos are produced as a beam extremely than isotropically. Nuclear bombs additionally produce very great numbers of neutrinos. Fred Reines and Clyde Cowan thought approximately attempting to come across neutrinos from a bomb in the previous they switched to searching for reactor neutrinos.

Answer 6

The neutrino is also required to conserve Lepton number. An electron, neutrino, tauon ,and muon all have Lepton numbers of 1, positrons, anti-neutrinos, anti-tauons, and anti-muons have Lepton number -1. When a neutron decays into an electron and a proton you start with a lepton number of 0 and end with a lepton number of 1. In order to balance this an anti-neutrino is also formed in the decay. The lepton number also has to be conserved by "flavor" an electron has a lepton flavor of electron, muon is muon flavored, tauon is tauon flavored. There are neutrinos with electron, tauon and muon flavorings.

Answer 7

Cosmic Gall

NEUTRINOS, they are very small.

They have no charge and have no mass

And do not interact at all.

The earth is just a silly ball

To them, through which they simply pass,

Like dustmaids down a drafty hall

Or photons through a sheet of glass.

They snub the most exquisite gas,

Ignore the most substantial wall,

Cold shoulder steel and sounding brass,

Insult the stallion in his stall,

And scorning barriers of class,

Infiltrate you and me! Like tall

and painless guillotines, they fall

Down through our heads into the grass.

At night, they enter at Nepal

and pierce the lover and his lass

From underneath the bed-you call

It wonderful; I call it crass.



John Updike

Answer 8

yes theyve been proved to exist by einstein and others, in the same way gravity and wind do by their effects.