Using the ForwArd Search ExpeRiment (FASER),a particle detector installed at CERN, particle physicists were able to detect very high energy neutrinos produced by CERN’s Large Hadron Collider (LHC).
The FASER Collaboration reports the first observation of collider neutrino events. Image credit: FASER Collaboration.
Neutrinos are fundamental particles that played an important role in the early phase of the Universe.
They are key to learn more about the fundamental laws of nature, including how particles acquire mass and why there is more matter than antimatter.
Despite being among the most abundant particles in the Universe they are very difficult to detect because they pass through matter with almost no interaction. They are therefore often called ghost particles.
Neutrinos have been known for several decades and were very important for establishing the standard model of particle physics.
But most neutrinos studied by physicists so far have been low-energy neutrinos. Previously, no neutrino produced at a particle collider had ever been detected by an experiment.
“Neutrinos, which were co-discovered nearly 70 years ago by the University of California, Irvine physicist and Nobel laureate Frederick Reines, are the most abundant particle in the cosmos and were very important for establishing the Standard Model of particle physics,” said Dr. Jamie Boyd, a particle physicist at CERN and co-spokesman for the FASER Collaboration.
“But no neutrino produced at a collider had ever been detected by an experiment.”
“We’ve discovered neutrinos from a brand-new source — particle colliders — where you have two beams of particles smash together at extremely high energy,” said Dr. Jonathan Feng, co-spokesman for the FASER Collaboration and a particle physicist at the University of California, Irvine.
The neutrinos detected by FASER are the highest energy ever produced in a lab and are similar to the neutrinos found when deep-space particles trigger dramatic particle showers in our atmosphere.
“They can tell us about deep space in ways we can’t learn otherwise,” Dr. Boyd said.
“These very high-energy neutrinos in the LHC are important for understanding really exciting observations in particle astrophysics.”
“Neutrinos are the only known particles that the much larger experiments at the LHC are unable to directly detect, so FASER’s successful observation means the collider’s full physics potential is finally being exploited,” said Dr. Dave Casper, an experimental physicist at the University of California, Irvine.
The FASER physicists presented their results on March 19, 2023 at the 57th Rencontres de Moriond.
Source : Breaking Science News