If you are looking from above, you will probably think this hole in the ground is actually a huge elevator shaft. But, this leads to experiment that might explain why matter didn’t disappear in a puff of radiation, a short time after the Big Bang happened.
Japan Proton Accelerator Research Complex
This is a remote government facility that is located in Tokai, almost an hour north of Tokyo. Here, there is an experiment going on, called T2K that actually produces a beam of the subatomic particles commonly known as neutrinos. The beam is able to travel through 296 km’s of rock up to the Super-K detector, which is a huge pit that is buried 1 km underground and it is filled with 50,000 tons of (ultrapure) water. While they are on the road of this journey, some neutrons will morph from one “flavor” into another.
In this ongoing experiment, researchers are studying all the ways how can these neutrinos flip in an effort to explain the predominance of matter over antimatter in the universe. With the data so far, the results are encouraging.
“According to the Standard Model of particle physics, every particle has a mirror-image particle that carries the opposite electrical charge — an antimatter particle. When matter and antimatter particles collide, they annihilate in a flash of radiation.”
But still, researchers still think that the Big Bang should’ve actually produce equal amounts of matter and antimatter, which will imply that everything vanished pretty quickly. Well, it appears that id didn’t! A very small piece of the matter managed to survive and somehow went on to form the universe we know.
Scientists don’t really know why.
Morgan Wascko, a physicist from the Imperial College London, said: “There must be some particle reactions that happen differently for matter and antimatter.”
Recently, the T2K collaboration has announced the very first evidence that neutrinos are actually able to break CP symmetry, which in a way explains why the universe is filled with matter.
Adrian Bevan, a physicist at Queen Mary University in London, stated: “If there is CP violation in the neutrino sector, then this could easily account for the matter-antimatter difference.”
Scientists check for CP violations by studying the main difference between the behavior of matter and antimatter. So, in 2016 – exactly 32 muon neutrinos have changed to electron neutrinos on their journey to Super-K. When muon antineutrinos were sent – only four of them appeared to become electron antineutrinos.
The scientific community got really excited by this discovery.
So, this year, scientists collected almost twice the amount of neutrino data from last year. The Super-K managed to capture 89 electron neutrinos, so significantly more in comparison if there wasn’t CP violation. This experiment actually spotted 7 electron antineutrinos, which is 2 fewer than expected.