A groundbreaking achievement in the field of particle physics has been made with the first-ever detection of neutrinos produced by a particle collider, with physicists from the University of Oregon (UO) playing a significant role in the international team responsible for the discovery. This new milestone in the study of the universe’s fundamental building blocks paves the way for answering pressing questions about the cosmos. The FASER (Forward Search Experiment) detector successfully captured high-energy neutrinos created by the Large Hadron Collider at CERN in Geneva, Switzerland, with the team announcing their findings on March 19 at a conference in Italy.
As the most abundant particles in the universe, neutrinos are crucial for understanding physics, yet they are incredibly challenging to study. Not only are they hundreds of thousands of times lighter than electrons, but they also barely interact with surrounding matter, making them elusive and hard to detect. Eric Torrence, UO physicist and collaborator on the project, said, “This is the first time we’ve seen neutrinos from any kind of collider experiment. It’s a whole new era of being able to measure neutrinos by looking at them directly in colliders.”
UO’s Department of Physics in the College of Arts and Sciences includes Torrence among its members. At the Large Hadron Collider, particles such as protons and electrons collide at nearly the speed of light, producing a multitude of other particle types. The FASER detector is strategically placed to capture the neutrinos generated by these high-energy collisions. Deion Fellers, a graduate student in Torrence’s lab who has been part of FASER from the beginning, explains that neutrinos can pass through rocks like ghosts, evading the initial particle explosion produced by the collider, whereas other particles decay or are absorbed soon after a collision.
These laboratory-generated, high-energy neutrinos fill a gap in the understanding of the particles by physicists. By measuring neutrinos and their interactions, scientists can check if experimental results match theoretical predictions and then estimate astrophysical phenomena. FASER’s ultimate goal is to uncover the nature of dark matter by exploring other elusive particles known as dark photons. Torrence and Fellers, along with postdoctoral researcher Daniela Koeck and graduate student Ansh Desai, are part of a 70-member international team collaborating with 24 universities worldwide. Torrence noted that this is a relatively small group for particle physics, with the team progressing from an initial proposal to a fully functional detector producing results in under four years. Although dark photons were not detected in this initial data set, the search has just begun. According to Torrence, establishing the project and obtaining these first results “was a real rush.”