A massive underground detector aimed at understanding the mysterious ghost particles in our universe released its first major results on Wednesday.
The Jiangmen Underground Neutrino Observatory (JUNO) in China started collecting data in August with the goal of understanding neutrinos: tiny cosmic particles that date back to the Big Bang and whiz harmlessly through our bodies by the trillions every second. Yet they weigh almost nothing, making them difficult to sniff out.
In a study published Wednesday in the journal Nature, the JUNO team unveiled its initial findings from two months of data collection — including some of the most precise measurements to date of how neutrinos switch between three varieties, or flavours, as they zip through space.
“It really makes me look forward to more exciting results in the future,” said physicist Kate Scholberg with Duke University, who had no role in the new research.
The spherical JUNO detector is located 2,297 feet (700 metres) underground. It examines antineutrinos that come from collisions inside two nearby nuclear power plants. Antineutrinos are equally mysterious, opposite versions of neutrinos that scientists can study to understand their behaviour and how neutrinos work.
When the antineutrinos meet particles within the detector, they produce a flash of light.
Scientists are hoping the detector will help resolve the long-standing mystery of how heavy each neutrino flavour is. They think two are similar in weight and that the third is an oddball, but they are not sure whether two are heavy and the other is light or vice versa.
The initial results have not answered that question just yet, but they show what the detector is capable of — and that it “will be able to test the finer ripples” that separate the neutrino flavours and their masses, said study co-author Liangjian Wen, a member of the JUNO collaboration.
Two similar neutrino detectors — Japan’s Hyper-Kamiokande and the Deep Underground Neutrino Experiment, based in the United States — are set to begin data collection within the next decade, cross-checking the China detector’s results using different approaches.
-AP
