FAST NEUTRINO OSCILLATIONS MAY HOLD KEY TO SUPERNOVAE FORMATION
12, May 2019
Why in News:
- Neutrinos could be the driving force behind supernova explosions, a new theoretical study finds.
- The study makes a fundamental advance in modelling neutrinos inside stars puts forth the idea that “fast neutrino oscillations” could hold the key to why some stars explode forming supernovae at the end of their lives.
- Neutrinos come in three flavours: electron neutrino, muon neutrino and tau neutrino, so named because of the corresponding leptons they are associated with (electron, muon and
tau).when measuring the number of neutrinos coming from the sun, experimentalists found that only a third of the number of solar neutrinos that was expected was being intercepted on earth. This was later explained by the understanding that they have a small mass and they can change from one flavour to another – a phenomenon named neutrino oscillations.
Fast neutrino oscillations
- When the same neutrinos are in the presence of many other neutrinos and when the different flavours are emitted slightly differently in various directions the oscillations from one flavour to another happen at a higher frequency.
- This is called fast oscillation and is proportional to the density of neutrinos in the medium, and not the masses of the neutrinos.
- Any star that collapses under its own gravity after having run out of its fusion fuel is called a supernova. Usually stars more massive than eight times the Sun’s mass enter this phase of explosive death.
- Collisions lead to the high anisotropy conditions. In the presence of collisions, the fast oscillations take place.
India-based Neutrino Observatory (INO):
- INO Project is aimed at building a world-class underground laboratory with a rock cover to conduct basic research on neutrino.
- The Tata Institute of Fundamental Research is the nodal institution. The observatory is to be built jointly with the Department of Atomic Energy and the Department of Science and Technology. The observatory will be located underground so as to provide adequate shielding to the neutrino detector from cosmic background radiation.
- The operation of INO will have no release of e of radioactive or toxic substances