Researchers within the MicroBooNE (Micro Booster Neutrino) collaboration have determined, with 95% probability, that a single sterile neutrino does not exist.
Utilizing data from the MicroBooNE detector, physicists announce one of the preliminary searches for sterile neutrinos with two accelerator neutrino beams. Image credit: Gemini AI.
Neutrinos are tiny subatomic particles that seldom interact with matter, allowing them to traverse the Earth without being impeded.
Current particle physics theory recognizes three types of neutrinos: electron, muon, and tau neutrinos.
These neutrinos can transform from one type to another, a phenomenon known as oscillation.
Previous experiments had revealed neutrinos that seemed to oscillate in ways not consistent with the standard model.
To clarify this anomaly, scientists suggested a fourth type: sterile neutrinos, which interact only through gravity, complicating their detection.
“The existence of three distinct flavors of neutrinos is a fundamental aspect of the Standard Model of particle physics,” explained Dr. Andrew Mastbaum, a physicist from Rutgers University and a member of the MicroBooNE leadership team.
“Because of quantum mechanical interference, neutrinos of one flavor can eventually be detected as a different flavor, a phenomenon known as neutrino oscillation.”
“Numerous unusual findings that challenge the three-flavor model have led us to postulate the existence of an additional neutrino state, referred to as a ‘sterile’ neutrino, which does not directly interact with matter.”
In the experiment conducted by MicroBooNE, physicists investigated neutrinos from two distinct beams and analyzed their oscillations.
After a decade of data gathering and scrutiny, they uncovered no evidence of sterile neutrinos, effectively rejecting one of the leading theories for the peculiarities observed in neutrino behavior.
“This result signifies a pivotal moment,” remarked Dr. Mastbaum.
“It will ignite innovative ideas in neutrino research, helping us to better comprehend the underlying phenomena.”
“While we can rule out major possibilities, this alone does not unravel the entire mystery.”
“The Standard Model does not encompass everything, such as dark matter, dark energy, and gravity, prompting scientists to seek clues that extend beyond the model,” he observed.
“By dismissing one potential explanation, we can concentrate on alternative hypotheses that may yield significant advancements in our understanding of the universe.”
The findings will also provide valuable insights for forthcoming experiments, like the Deep Underground Neutrino Experiment (DUNE).
“Through meticulous modeling and a strategic analytical approach, the MicroBooNE team has extracted an extraordinary amount of information from this detector,” stated Dr. Mastbaum.
“In next-generation projects like DUNE, we are already utilizing these techniques to explore even more fundamental questions about the essence of matter and the nature of the universe.”
of the team results published in the journal Nature.
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Collaboration with MicroBooNE. 2025. Search for photosterile neutrinos using two neutrino beams with MicroBooNE. Nature 648, 64-69; doi: 10.1038/s41586-025-09757-7
Source: www.sci.news
