Muon neutrino
Encyclopedia
The muon neutrino
is a subatomic
lepton
elementary particle
which has the symbol and no net electric charge
. Together with the muon
it forms the second generation of leptons, hence its name muon neutrino. It was first hypothesized in the early 1940s by several people, and was discovered in 1962 by Leon Lederman, Melvin Schwartz
and Jack Steinberger
. The discovery was rewarded with the 1988 Nobel Prize in Physics
.
, Melvin Schwartz
and Jack Steinberger
showed that more than one type of neutrino exists by first detecting interactions of the muon
neutrino (already hypothesised with the name neutretto), which earned them the 1988 Nobel Prize
.
researchers observed muon neutrinos traveling apparently at faster
than lightspeed (see: OPERA neutrino anomaly
). This result was confirmed again in a second November experiment. These results have been viewed sceptically by the scientific community at large, and more experiments are underway to further investigate the phenomenon.
Neutrino
A neutrino is an electrically neutral, weakly interacting elementary subatomic particle with a half-integer spin, chirality and a disputed but small non-zero mass. It is able to pass through ordinary matter almost unaffected...
is a subatomic
Subatomic particle
In physics or chemistry, subatomic particles are the smaller particles composing nucleons and atoms. There are two types of subatomic particles: elementary particles, which are not made of other particles, and composite particles...
lepton
Lepton
A lepton is an elementary particle and a fundamental constituent of matter. The best known of all leptons is the electron which governs nearly all of chemistry as it is found in atoms and is directly tied to all chemical properties. Two main classes of leptons exist: charged leptons , and neutral...
elementary particle
Elementary particle
In particle physics, an elementary particle or fundamental particle is a particle not known to have substructure; that is, it is not known to be made up of smaller particles. If an elementary particle truly has no substructure, then it is one of the basic building blocks of the universe from which...
which has the symbol and no net electric charge
Electric charge
Electric charge is a physical property of matter that causes it to experience a force when near other electrically charged matter. Electric charge comes in two types, called positive and negative. Two positively charged substances, or objects, experience a mutual repulsive force, as do two...
. Together with the muon
Muon
The muon |mu]] used to represent it) is an elementary particle similar to the electron, with a unitary negative electric charge and a spin of ½. Together with the electron, the tau, and the three neutrinos, it is classified as a lepton...
it forms the second generation of leptons, hence its name muon neutrino. It was first hypothesized in the early 1940s by several people, and was discovered in 1962 by Leon Lederman, Melvin Schwartz
Melvin Schwartz
Melvin Schwartz was an American physicist. He shared the 1988 Nobel Prize in Physics with Leon M. Lederman and Jack Steinberger for their development of the neutrino beam method and their demonstration of the doublet structure of the leptons through the discovery of the muon neutrino.He grew up in...
and Jack Steinberger
Jack Steinberger
Jack Steinberger is a German-American physicist currently residing near Geneva, Switzerland. He co-discovered the muon neutrino, along with Leon Lederman and Melvin Schwartz, for which they were given the 1988 Nobel Prize in Physics.-Life:...
. The discovery was rewarded with the 1988 Nobel Prize in Physics
Nobel Prize in Physics
The Nobel Prize in Physics is awarded once a year by the Royal Swedish Academy of Sciences. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895 and awarded since 1901; the others are the Nobel Prize in Chemistry, Nobel Prize in Literature, Nobel Peace Prize, and...
.
Discovery
In 1962 Leon M. LedermanLeon M. Lederman
Leon Max Lederman is an American experimental physicist and Nobel Prize in Physics laureate for his work with neutrinos. He is Director Emeritus of Fermi National Accelerator Laboratory in Batavia, Illinois, USA...
, Melvin Schwartz
Melvin Schwartz
Melvin Schwartz was an American physicist. He shared the 1988 Nobel Prize in Physics with Leon M. Lederman and Jack Steinberger for their development of the neutrino beam method and their demonstration of the doublet structure of the leptons through the discovery of the muon neutrino.He grew up in...
and Jack Steinberger
Jack Steinberger
Jack Steinberger is a German-American physicist currently residing near Geneva, Switzerland. He co-discovered the muon neutrino, along with Leon Lederman and Melvin Schwartz, for which they were given the 1988 Nobel Prize in Physics.-Life:...
showed that more than one type of neutrino exists by first detecting interactions of the muon
Muon
The muon |mu]] used to represent it) is an elementary particle similar to the electron, with a unitary negative electric charge and a spin of ½. Together with the electron, the tau, and the three neutrinos, it is classified as a lepton...
neutrino (already hypothesised with the name neutretto), which earned them the 1988 Nobel Prize
Nobel Prize in Physics
The Nobel Prize in Physics is awarded once a year by the Royal Swedish Academy of Sciences. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895 and awarded since 1901; the others are the Nobel Prize in Chemistry, Nobel Prize in Literature, Nobel Peace Prize, and...
.
Speed
In September 2011, OPERAOPERA Experiment
The Oscillation Project with Emulsion-tRacking Apparatus is a scientific experiment for detecting tau neutrinos from muon neutrino oscillations. It is a collaboration between CERN in Geneva, Switzerland, and the Laboratori Nazionali del Gran Sasso in Gran Sasso, Italy and uses the CERN Neutrinos...
researchers observed muon neutrinos traveling apparently at faster
Faster-than-light
Faster-than-light communications and travel refer to the propagation of information or matter faster than the speed of light....
than lightspeed (see: OPERA neutrino anomaly
OPERA neutrino anomaly
The OPERA neutrino anomaly is the detection of apparently faster-than-light neutrinos by the OPERA experiment as publicly announced in September 2011. The detection is anomalous because speeds exceeding that of light in a vacuum are generally thought to violate special relativity, a prevailing...
). This result was confirmed again in a second November experiment. These results have been viewed sceptically by the scientific community at large, and more experiments are underway to further investigate the phenomenon.