For what gave Nobel Prize on physics this year: neytrinny ostsillyatsiya
On Tuesday the Nobel committee declared two scientists, Takaaki Kadzhita from Japan and Arthur McDonald from Canada, Nobel prize winners on physics for their experiments with detection neytrino. Kadzhita and McDonald directed two groups (in observatories on the opposite ends of a planet) in search of imperceptible particles neytrino and the solution of an old problem in physics of particles.
McDonald, the professor of Royal university in the Valve, told what to get the Nobel premium "was very difficult". «Fortunately — he added — I have many colleagues who will divide this prize with me. They did a work large quantity to execute these measurements».
Kadzhita, the professor of the Tokyo university, told what to win a prize «some kind of it was improbable». «I think, importance that — and it is exact — outside of Standard model is available physics» — he added.
What is neytrino?
Neytrino is small elementary particles which are formed in nuclear reactions, like synthesis reactions in the Sun or division reactions on our nuclear power plants. These particles are independent of gravitation or electromagnetism that does them by "poorly cooperating" particles. In spite of the fact that every second the Sun lets out trillions neytrino, billions from which reach Earth, almost all pass through a planet, touching nothing.
As neytrino pass almost through everything, to find them quite difficult. Deeply underground huge detectors of particles which can avoid hindrances from the space beams which are forming in the atmosphere are constructed. These detectors consist of several big tanks of the water which sensors constantly wait at least for one interaction with neytrino. There is a hope that from billions neytrino which pass through water резевруары, at least the couple will face a kernel of atom of water and will make enough radiation that the sensor could catch it.
Problem solar neytrino
Neytrino happen three types: electronic, muonic and tau-neytrino. Electronic neytrino are most widespread, they are made in the Sun center. As we know extent of reactions of synthesis of the Sun, we can estimate quantity electronic neytrino which makes the Sun every second.
But when we compare this assessment to our neytrinny measurements on Earth, we are at a deadlock. The number solar neytrino, found out on Earth, three times is less than that should be, and long time scientists were in perplexity.
The possible answer appeared in the late nineties when some scientists assumed that problems follows from neytrinny ostsillyatsiya, process during which one type neytrino like the electronic is spontaneously transformed to other type, muonic or тау. Our detectors solar neytrino on Earth are adjusted only on detection electronic neytrino therefore if two thirds solar neytrino will be transformed on the way to us, we will find only their small part.
In 1998 the team under the direction of Kadzhita on the detector of Super-Kamiokande received the first concrete proofs of ostsillyatsiya neytrino. Scientists measured quantity muonic neytrino, being formed in the atmosphere, as over the detector, and coming from the opposite end of Earth. The group found out that the detector catches much less neytrino, passing through Earth, through thousands kilometers from it, than that appear over it. It shows that on the way a set muonic neytrino disappear, and the ostsillyatsiya neytrino will be the best explanation.
The final proof came from neytrinny observatory of Sudbury where McDonald which was the first detector solar neytrino worked, capable to find muonic and tau-neytrino, in addition to electronic neytrino. The Sudbury team quickly found proofs of existence of two other types, having confirmed that neytrino from the Sun are really transformed on the road here.
To put it briefly, this result strengthened idea of neytrinny ostsillyatsiya in physical community.
The Nobel Prize of this year finished total number of physicists winners to 201. On Monday the Nobel committee declared award of the Nobel Prize in the field of physiology or medicine to William Campbell and Satoshi Omura for their work on drugs for fight against parasites.