The Portuguese team is part of XENON, an international collaboration involving scientists from around 30 countries. The experiment was originally created to search for dark matter, the invisible material believed to make up a large part of the universe.

The latest results have now shown that the same technology can detect extremely rare interactions involving neutrinos.

For the first time, the experiment was able to reach neutrino energies as low as 17 keV, or kiloelectronvolts, a level that the University of Coimbra describes as unprecedented.

Neutrinos are among the most common particles in the universe and are produced through processes including nuclear reactions inside the Sun. Billions pass through every square centimetre of the Earth's surface every second – including through our bodies – without us noticing.

They are extremely difficult to detect because they very rarely interact with matter.

The XENON experiment is installed around 1,300 metres underground at the Gran Sasso National Laboratory in Italy. Its location deep below the surface helps protect its detectors from other radiation that could interfere with the extremely faint signals scientists are trying to find.

Although the system was developed primarily to search for dark matter, the latest results demonstrate that it can also be used to investigate neutrinos and other extremely rare events.

The Portuguese researchers involved come from the Department of Physics at the University of Coimbra's Faculty of Sciences and Technology, with the team coordinated by José Matias Lopes.

The university says the achievement is the result of more than two decades of technological development within the international XENON collaboration.

By making it possible to detect increasingly faint signals, researchers hope the technology can help scientists better understand some of the fundamental particles and mysteries of the universe.