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

TL;DR

The paper reports initial KATRIN neutrino mass results aligning with a new upper limit and also compatible with an exotic 3+3 neutrino mass model involving a tachyonic state, pending further data.

Contribution

It presents the first KATRIN results and explores their compatibility with an unconventional 3+3 neutrino mass model including a tachyonic state.

Findings

KATRIN sets an upper limit of 1.1 eV on neutrino mass.

Results are consistent with an exotic 3+3 neutrino model.

Further data will test the model's validity.

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.