Japan proposed the world's largest neutrino detector

　　Science and Technology Daily Beijing December 18 (Reporter Liu Xia) According to the British "Nature" magazine website reported that the Japanese cabinet has approved plans to build a "top-Kamiokande" neutrino detectors, and agreed to allocate $ 32 million as the first construction costs. Scientists hope the probe "giant" can bring a revolutionary discovery, to deepen understanding of the differences in the behavior of neutrinos and antineutrinos, and to detect proton decay and so on.
　　"Top-Kamiokande" is Japan's existing "Super-Kamiokande" probe "successor." In 1998, the "Super-Kamiokande" provides the first conclusive evidence for neutrino oscillations, the head of Yuki Takashi Chapter 2015 Nobel Prize in Physics to send the podium. "Top Kamioka," which will become by far the largest neutrino detector.
　　"Top Kamioka" will be built in the city of Gifu Prefecture underground missile, capable of detecting the neutrino mass from various sources of cosmic rays, the sun, and particle accelerators such as supernova produced. Facilities body diameter 68 m, a depth of about 71 m, storage 260,000 tons, the "Super-K" is more than five times, the wall of the pool of about 40,000 photomultiplier tube, may be emitted to capture the micro-reaction with water neutrinos Light.
　　Yuki Takashi Chapter 16, said the arrival of neutrino physicists "top-Kamiokande" is filled with hope, because it can study differences in behavior of neutrinos and antineutrinos, which helps explain why the universe seems a matter leading. "Super-Kamiokande" has seen some "clues", but "top-Kamiokande" and the US "deep underground neutrino experiment" (DUNE, using liquid argon) should be able to use different techniques to achieve high-precision measurement, thus corroborated each other. DUNE will be launched in 2025. In addition to these two "giants", the one located in Guangdong, China's "Jiangmen underground neutrino experiments (JUNO)" also three major neutrino experiment in the 1920s will begin to run, it will begin collecting 2021 data.
　　Tokyo University physicist, "Super-Kamiokande" the spokesman Masayuki Shimizu said, "the top-Kamiokande" is also expected to find proton decay. Proton decay has never been observed, and therefore extremely rare, which means that the average life expectancy of protons over 34 th of October.
　　In the standard model of particle physics, the proton can not decay, but many attempts to replace the standard model theory predicted proton decay. As the "top-Kamiokande" far more than the amount of water used to detect neutrinos, "former" and therefore more likely to observe proton decay. If not, that means the average life expectancy of protons will increase tenfold.
　　It is reported that "top-Kamiokande" total cost of about $ 600 million, Japan will provide about 75% of the remaining funds will be paid by the United Kingdom and Canada. Japanese physicist said the Japanese parliament could formally approve the project next month.
　　<strong> editor punctuate </ strong>
　　in Japan, "top-Kamiokande" is considered the Nobel Prize of harvesting it is expected to help scientists probe. The reason is that, although we are known around full of substance, but so far is not clear why the initial substances exist in the universe. After the birth of the universe, should have the same amount of material as well as the existence of antimatter, but then the matter will be destroyed, it can not produce stars and all living things. Would like to solve this mystery, the key is the neutrino. What if the influence of neutrinos, matter and antimatter was challenged balanced? This presumably would be "top-Kamiokande" verify it? Whether the huge investment of LHC detectors can bring the same year as the dawn? Entire elementary particle physics community, are waiting to see.