Friday 06 June 2025
Scientists have been searching for a way to detect relic neutrinos, particles that were born in the early universe and are thought to be abundant today. Now, researchers claim they’ve found a new avenue for detecting these elusive particles: using ultra-high-energy cosmic rays.
Neutrinos are among the most mysterious particles in the universe. They’re created during high-energy processes, such as supernovae explosions or the collision of protons with other particles. However, they rarely interact with matter, making them extremely difficult to detect.
One way scientists have tried to detect neutrinos is by using large detectors, like IceCube at the South Pole, which looks for the faint signals left behind when a neutrino interacts with a nucleus in the detector’s ice. But this method has limitations: it can only detect high-energy neutrinos, and even then, it’s a challenge.
Enter ultra-high-energy cosmic rays (UHECRs), particles that zoom through space at nearly light-speed. These particles are thought to be accelerated by powerful astrophysical sources, such as active galactic nuclei or supernovae remnants. When UHECRs interact with the cosmic neutrino background, they can produce neutrinos that are detectable on Earth.
Researchers have developed a new model that takes into account the interactions between UHECRs and relic neutrinos. They’ve calculated the expected flux of boosted neutrinos at Earth, using data from IceCube and the Pierre Auger Observatory. The results show that, if relic neutrinos exist in sufficient numbers, they could be detected by current experiments.
The team also explored the impact of different lightest neutrino masses on the detection prospects. They found that a smaller lightest neutrino mass reduces the boosted neutrino flux, but only up to a point. Below a certain threshold, the flux remains relatively constant.
Furthermore, the researchers investigated the effect of an inverted neutrino mass ordering on the boosted neutrino flux. They discovered that this ordering leads to a significant increase in the detected neutrino flux at low masses.
These findings open up new avenues for detecting relic neutrinos and could potentially shed light on the nature of these enigmatic particles. While the results are still theoretical, they demonstrate the potential power of using UHECRs as a probe of the cosmic neutrino background.
In the future, scientists may be able to use this method to detect relic neutrinos and gain insights into the early universe.
Cite this article: “Detecting Relic Neutrinos with Ultra-High-Energy Cosmic Rays”, The Science Archive, 2025.
Neutrinos, Cosmic Rays, Relic Neutrinos, Ultra-High-Energy, Detection, Icecube, Pierre Auger Observatory, Neutrino Background, Astrophysical Sources, Particle Physics
