A 2019 paper published in Advances in Astronomy, summarizes all the evidence found in support of one of the neutrinos being a tachyon prior to the KATRIN experiment.* This evidence relies on analyses of previously published data, coming from fields including cosmic ray physics, particle physics and astrophysics. It also includes one theoretical argument, involving a new dark matter model of supernova SN 1987A. Although this 2019 paper will not be intelligible to most non-physicists, there is a tachyon powerpoint presentation that is intended for everyone. Most of the other links on the home page should also be intelligible to non-physicists, particularly “my tachyon prediction“ and the book “Hunting the Tachyon.” The KATRIN experiment now underway in Germany should within a year have enough data to provide definitive evidence for or against the 3 + 3 model of the neutrino masses. This model, which was proposed in a 2013 paper, calls for one of the neutrinos being a tachyon having a specific imaginary mass. The first results of KATRIN published in September 2019 are consistent with both the conventional neutrino mass model and the 3 + 3 model.
*One piece of evidence presented, however, was a mistake as spelled out in this paper.