First results of the KATRIN neutrino mass experiment and their consistency with an exotic $3+3$ model

Abstract

Although the first results of the KATRIN neutrino mass experiment are consistent with a new improved upper limit of 1.1 eV for the effective mass of the electron neutrino, surprisingly they are also consistent with an exotic model of the neutrino masses put forward in 2013 that includes one tachyonic mass state doublet having $m^2\sim - 0.2$ keV$^2$. A definitive conclusion on the validity of the model should be possible after less than one year of KATRIN data-taking.