Neutrinos, the tiny and neutrally charged particles, have long remained a challenge for particle physicists. Although they are believed to be abundant in the universe, detecting them has been difficult due to their low interaction probability with matter. However, recent breakthroughs in experimental particle physics research have led to the observation of neutrinos inside colliders for the first time. Two large research collaborations, FASER (Forward Search Experiment) and SND (Scattering and Neutrino Detector)@LHC, have successfully detected collider neutrinos using detectors located at CERN’s Large Hadron Collider (LHC) in Switzerland. These groundbreaking discoveries open up new avenues for studying neutrinos and furthering our understanding of the fundamental properties of the universe.
Neutrinos are the least well-studied particles in the Standard Model of particle physics, mainly due to their weak interaction with other particles. Their detection has posed a significant challenge for scientists, as they do not easily interact with matter. Despite being produced abundantly in proton colliders like the LHC, neutrinos had never been directly observed inside colliders until now. The weak interaction of neutrinos necessitated the use of advanced detection techniques and equipment to observe these elusive particles.
The FASER collaboration, a prominent research effort focused on observing light and weakly interacting particles, was the first to detect neutrinos at the LHC. By placing their detector at a strategic distance of over 400m from the ATLAS experiment, the FASER collaboration successfully observed neutrinos produced in the same “interaction region” inside the LHC. Previous particle colliders had detected every known particle except neutrinos, making this discovery a significant milestone in particle physics research.
The SND@LHC collaboration, another research effort at the LHC, also achieved the successful detection of collider neutrinos. Their detector, strategically positioned at a site with a high flux of neutrinos but shielded from proton collision debris, recorded a significant number of neutrino events. Overcoming the challenge of background interference from muons produced in the collisions, the collaboration analyzed data collected during its first operation cycle.
The observation of collider neutrinos holds immense significance for the field of particle physics. Not only does it open the door to novel measurements that can help solve fundamental puzzles of the Standard Model, but it also enables a better understanding of the structure of colliding protons. Furthermore, the high-energy neutrinos detected by both collaborations have the potential to pave the way for in-depth studies of neutrino properties and searches for other elusive particles. These breakthroughs demonstrate the convergence of high-energy and high-intensity particle physics experiments, bridging the gap between different realms of particle physics research.
The recent advances made by the FASER and SND@LHC collaborations have set the stage for further advancements in experimental particle physics research. Both groups will continue collecting data at the LHC to gather more meaningful observations. The FASER collaboration plans to run their detector for many more years and expects to collect at least ten times more data, utilizing the full power of their detector to study high-energy neutrino interactions in great detail. Additionally, the proposed construction of the Forward Physics Facility, an underground cavern at the LHC, could further enhance neutrino detection capabilities and facilitate the exploration of phenomena associated with dark matter.
The recent observation of neutrinos inside colliders marks a significant breakthrough in particle physics research. The efforts of the FASER and SND@LHC collaborations have demonstrated the detection of collider neutrinos and their potential for unraveling the mysteries of the universe. By successfully overcoming the challenges associated with weakly interacting particles, these experiments have provided valuable insights into the properties of neutrinos and the structure of colliding protons. With continued advancements in experimental techniques and detector technology, further breakthroughs in neutrino research are on the horizon, promising to revolutionize our understanding of the fundamental building blocks of the universe.