The Large Hadron Collider has been used to detect every known particle except neutrinos. Until now

Neutrinos are some of the most enigmatic particles in all of physics. FASER detected the neutrinos by arranging its detector along the line of a particle beam in such a way that the highest energy neutrinos would pass through it. "Previously, particle physics was thought to be divided into two parts: high energy experiments, which were required to study heavy particles, like top quarks and Higgs bosons, and high intensity experiments, which were required to study neutrinos," Jonathan Lee Feng, co-spokesperson of the FASER Collaboration, told Phys.org. "This work has shown that high energy experiments can also study neutrinos, and so has brought together the high-energy and high-intensity frontiers." "Particle colliders have existed for over 50 years, and have detected every known particle except for neutrinos," he added.