Japan wants to build the largest neutrino detector in history with the Super Kamiokande project after a Cabinet committee approved billions of yen for its construction on December 13. This was reported by the scientists involved in the future project. The new Super Kamiokande will hold 260,000 tonnes of ultra-pure water. That's more than five times the amount contained in its already giant sibling. Researchers want to build the new neutrino detector in a huge cave. This will then be excavated next to the Kamioka mine in Hida. The scientific project will, physicists hope, bring groundbreaking discoveries about these ubiquitous particles.
New hyper project after Super Kamiokande
The enormous size of the Hyper Kamiokande (Hyper-K) allows it to detect an unprecedented number of neutrinos. Various sources can generate these. This includes cosmicRadiation, sun, supernovaand rays that come artificially from an existing particle accelerator. In addition to collecting neutrinos, researchers are monitoring the water for the possible spontaneous decay of protons in atomic nuclei. That in itself, if you look at it that way, would be a revolutionary discovery.
Although the government has not yet made an official statement on the approval, several scientists have said that the country's Cabinet will transfer the first annual grant of 3.5 billion yen ($32 million) for construction. The government approved this as part of an addendum for the current budget year. However, Parliament should first regulate the financial aspects. This is expected to happen next month, sayJapanese scientistsand physicists.
Precision measurements
Neutrino physicists are excited about Hyper-K because it can study differences in the behavior of neutrinos and their anti-matter counterparts, antineutrinos, at a conference in London on December 16. This is what Takaaki Kajita, a physicist at the University of Tokyo, said. Such asymmetry could explain why the universe appears to contain mostly matter and little antimatter. This was said by Kajita, who won the 2015 Nobel Prize in Physics for his discovery of neutrino oscillations. The scientists made these with the Super Kamiokande in the 90s.
Super-K has already seen evidence of this discrepancy, but both Hyper-K and DUNE should be able to measure it with high accuracy using two different techniques - DUNE uses liquid argon instead of water, providing an important comparison. “They have similar sensibilities, but for me complementarity is an important aspect,” said Kajita.
The biggest discovery Hyper Kamiokande can make is proton decay, says Masayuki Nakahata, a physicist at the University of Tokyo. He is also a spokesperson for the Super Kamiokande project, which is an international collaboration led by Japan and the United States. Proton decay has never been observed and therefore must be extremely rare, if at all, meaning that the proton has a very long average lifespan of more than 1034 years.
The current Standard Model of particle physics does not allow for proton decay, but many of the theories that have been proposed to replace it and unify the fundamental forces of nature predict the phenomenon. Because Hyper-K monitors a much larger volume of water than Super-K, it has a better chance of observing the decay of protons. If it fails to detect the phenomenon, the limit on the proton's average lifetime will increase tenfold.
