Neutrinos explain where all the missing antimatter universe


12/03/2012

Neutrinos are produced by a nuclear reactor in China, mutate from one form to another more quickly than expected. This may help explain why the universe is filled with matter and radiation is not uniform.

Neutrinos and antineutrinos as, is of three types: electron, muon and tau. As they pass through the space, they can be converted from one form to another.

Changing the type measured by three parameters, the so-called mixing angles: teta12, teta23 and teta13. Until recently, only the first two corners of the mixing were measured. But in June of last year, during the T2K experiment in Japan, researchers have demonstrated the transformation of muon neutrinos into electron neutrinos, and the pre-calculated value teta13.

The problem is that they depend on other observation angles mixed. "This was caused by the difficulty determining the exact value of teta13" - said Kam-Beau Luc University of California at Berkeley. Researchers from the Daya Bay in southern China conducted a new experiment, during which they are made precise calculations.

During the experiment in Daya Bay, electron antineutrinos emitted by six nuclear reactors. Measurements were carried out two sets of sensors, one of which was at a distance of several hundred meters from the reactor and the other at a distance of 2 kilometers. The farther away from the reactors, the less electron antineutrinos, because as the passage of a distance, some converted into another type of antineutrino that these sensors do not detect.

The results were announced on March 8 at a seminar at the Institute of High Energy Physics in Beijing. "Finally, we became aware of the size teta13. It is not as small as it was thought before."

"The consequences of this will be enormous," - said Francis Halzen, who heads a neutrino observatory "IceCube" at the South Pole. These results will allow physicists to conduct experiments to determine the differences in the behavior of neutrinos and antineutrinos. If the value teta13 was small, the holding of such experiments would be difficult.

These experiments will determine why the universe established the predominance of matter over antimatter in the first moments after the Big Bang. Without such a bias, the whole matter would have been annihilated antimatter.

"Size teta13 exceeded our wildest expectations - this is a striking result, which is definitely far advance neutrino physics," - said Halzen. "Now we know which direction to go next."

Original: Newscientist


Astronomers have discovered the fastest pulsar
The most powerful camera showed the presence of water on Mars
In Chelyabinsk meteorite discovered nanocrystals olivine
Russia sends astronauts to the ISS after an unprecedented series of failures
The gas cloud glows 100 times brighter than the sun in the center of the galaxy