Muon neutrinos (denoted as ν μ ) - an elementary particle , which is one of the three types of neutrinos . Together with the muon, it is the second generation of leptons . [1] .
| Muon neutrino (ν μ ) | |
|---|---|
| Composition | fundamental particle |
| Family | Fermions |
| Group | Leptons |
| Generation | second |
| Involved in interactions | weak gravitational |
| Weight | less than 0.28 eV but not zero |
| Lifetime | stable |
| Decay channels | not |
| Quantum numbers | |
| Electric charge | 0 |
| Baryon number | 0 |
| Lepton number | +1 |
| Spin | ½ ħ |
| Detected | Leon Lederman , Melvin Schwartz and Jack Steinberger (1962) |
Content
Properties
Like other types of neutrinos, muon neutrinos are prone to oscillations . Thus, at a certain distance from the place of their radiation, the probability of detecting neutrinos of other types changes periodically.
Opening
The hypothesis of the existence of another type of neutrino (except for the already known electron) was proposed in the 1940s. The particle was experimentally discovered in 1962 by a group of researchers led by Leon Lederman , Melvin Schwartz and Jack Steinberger . For this discovery, scientists were awarded the Nobel Prize in Physics in 1988.
Possible superluminal movement
A group of researchers working with the OPERA detector (and MINOS , 2007 [2] [ specify ] ), at CERN , the world's largest nuclear physics research laboratory, published the results of its measurements, from which it follows that muon neutrinos are able to move faster than the speed of light [3] . Experts questioned the results, since they do not agree not only with the theory of relativity, but also with other experiments with neutrinos [4] . On February 23, 2012, CERN reported that the OPERA collaboration identified two factors that could cause measurement errors [5] [6] .
Independent measurements in the same tunnel of superluminal velocities of neutrinos were not found soon in March 2012 [7] . In May 2012, OPERA conducted a series of control experiments and came to the final conclusion that the cause of the erroneous conclusion about superluminal speed was a technical defect (poorly inserted optical cable connector) [8] .
See also
- Electron neutrino
- Tau neutrino
Notes
- ↑ Muon. Muon neutrino
- ↑ In 2007, a similar experiment was conducted on the MINOS detector, and also gave a neutrino velocity higher than the speed of light by about 0.005% with a confidence of about 70%.
- ↑ Sensation refuting the foundations of physics: speed of light exceeded // newsru.com
- ↑ OPERA experiment reports on the observation of superluminal velocity of neutrinos // Elements.ru, September 23, 2011
- ↑ OPERA experiment reports anomaly in flight time of neutrinos from CERN to Gran Sasso
- ↑ Official statement
- ↑ ICARUS Collaboration et al. Measurement of the neutrino velocity with the ICARUS detector at the CNGS beam // Physics Letters B. - 2012. - Vol. 713 (July 18). - P. 17–22. - arXiv : 1203.3433 . - DOI : 10.1016 / j.physletb.2012.05.05.033 .
- ↑ OPERA experiment finally “closed” superlight neutrinos .
Links
- Kabin E. Neutrino Physics // Popular Science Lecture on Elementy.ru