By Jenni Davidson
Physicists from the University of Sussex are celebrating the first sightings of the miniscule particles known as neutrinos.
Dr Jeff Hartnell and a team from the university have been working with other scientists from across the globe for the past 18 months on the world’s longest-distance neutrino experiment.
The NOvA experiment consists of two huge particle detectors placed 500 miles apart in Chicago and Minnesota.
Its aim is to explore the properties of an intense beam of subatomic particles called neutrinos.
Dr Hartnell said: “Observing our first neutrinos is a really important milestone for Sussex, NOvA and the global physics community: we have demonstrated that our experiment is working.”
Neutrinos are abundant in the atmosphere, but they have barely any mass and very rarely interact with other matter.
Many of the neutrinos around today are thought to have originated in the Big Bang and studying them could yield information about the early moments of the Universe.
Physicists believe that the Big Bang created equal amounts of matter and antimatter.
When corresponding particles of matter and antimatter meet, they destroy one another.
But matter is still here, and antimatter has, for the most part, vanished.
Scientists believe that neutrinos could hold the key to understanding this mystery.
One goal of the NOvA experiment is to determine the order of the neutrino masses, known as the mass hierarchy.
This will help scientists narrow their list of possible theories about how neutrinos work.
The detector produces light when charged particles pass through it.
The Sussex team has played a crucial role in calibrating and fine-tuning the neutrino detector.
“Our next task is to complete the detector and collect the data that will allow us to push back the boundaries of knowledge about neutrinos and work towards answering the big question of why the universe is dominated by matter and not antimatter,” said Dr Hartnell.
Only a fraction of the larger detector, in Minnesota, has been completed, but it has already recorded signals from its first neutrinos.
Once finished, it will measure 200 feet in length and weigh 14,000 tons.
The detector is due to be completed later this year, and the first series of experiments will last for six years.