Fusion in the sun results in electron neutrinos and scientists have predicted that if they can measure the electron neutrinos coming from the sun, they can measure the core of the sun. However, early experiments showed that less than half the expected neutrinos were observed on Earth. The idea that the missing electron neutrinos may have transformed into another type or “flavor” came alive.
This conclusion indicates that neutrinos do have some mass, small as it may be, in order for them to oscillate. So a portion of the electron neutrinos emitted from the sun could have changed flavors to muon or tau neutrinos before reaching Earth, thus solving the missing neutrino problem.
But it still doesn’t explain how or why this occurs, Barnes said. “Our goal is to understand the flavor oscillation properties of neutrinos,” he said.
Studying the elusive neutrino will help scientists better understand particle physics, specifically how particles acquire mass, as well as its role in the formation of the universe and its relationship to dark matter.
From a DOE press release.