In 2020, the T2K Collaboration reported some indications of CP violation in leptons for the first time. In this experiment, beams of muon neutrinos (ν μ) and muon antineutrinos (ν μ) were alternately produced by an accelerator. By the time they got to the detector, a significantly higher proportion of electron neutrinos (ν e) were detected from the ν μ beams, than electron antineutrinos (ν e) were from the ν μ beams. The results were not yet precise enough to determine the size of the CP violation, relative to that seen in quarks. In addition, another similar experiment, NOvA sees no evidence of CP violation in neutrino oscillations and is in slight tension with T2K.