With a small ceremony at the Sanford Underground Research Facility (SURF) in South Dakota (United States) the construction has begun of a large international experiment that could deliver an important contribution to our knowledge of the universe. The Long Baseline Neutrino Facility (LBNF) will (in 10 years, when the construction is completed) house the international Deep Underground Neutrino Experiment (DUNE). During the construction and later when DUNE is in use, a group of about 1000 researchers and engineers from 30 countries will be participating.

LBNF/DUNE will be the largest experiment in the US that will study the characteristics of the mysterious elementary particles that are called neutrinos. Unraveling the characteristics of these particles could give an answer to the question how our universe works and why matter can exist.

The Fermi National Accelerator Laboratory (Fermilab), in the vicinity of Chicago, will generate neutrinos for this purpose, which will then be sent 1300 kilometers through the Earth to the Sanford Lab and will be detected there in a four story high underground detector weighing 70 thousand tons.

In the detector, the interaction of neutrinos with other particles will be studied. Also, the differences between neutrinos and anti-neutrinos (the corresponding anti-particles) will be examined. This could give an indication why the visible universe is dominated by (ordinary) matter.