A possible new sterile neutrino violates the "charge-parity symmetry" of the universe

Recent results on the high-profile Fermilab physics experiment Mini Booster Neutrino Experiment, MiniBooNE, suggest the existence of a new elementary like-neutrino particle: a fourth flavor of neutrino. Scientists previously believed three flavors of neutrino exist, but researchers detected in MiniBooNE more oscillations than would be possible if there were only three flavors.This mean "that there are either new particles or forces we had not previously imagined," said Byron Roe, professor emeritus in the Department of Physics, and an author of the paper "Event Excess in the MiniBooNE Search for ν̅ μ→ν̅ e Oscillations". However this fourth flavor would not interact through the weak force, making it harder to find.

This possible new sterile neutrino is on the mouth of physicists and astronomers because it could possible help to understand the matter-antimatter asymmetry of the universe and why the universe is primarily composed of matter, rather than antimatter. Another non less important conclusion is that results seems to violate the "charge-parity symmetry" of the universe, and then the laws of physics could not be applied in the same ways to particles and their counterpart antiparticles.

Even if the results are statistically significant and confirm previously findings (see LSND experiment), the researchers caution that results over longer periods of time are necessary before any change of the actual standard model.

More @ University of Michigan

Full paper available hereafter :
Event Excess in the MiniBooNE Search for Vmu to Ve Oscillations