KATRIN sensitivity on right-handed currents with light sterile neutrinos

The KATRIN experiment aims to determine the absolute neutrino mass by measuring the endpoint of the Tritium beta spectrum. As a large-scale experiment with a sharp energy resolution, high source luminosity and low background it may also be capable of testing certain theories of neutrino interactions beyond the standard model (SM). An example of a non-SM interaction are right-handed currents mediated by right-handed W bosons in the left-right symmetric model (LRSM). In this extension of the SM, an additional SU(2)_R symmetry in the high-energy limit, which naturally predicts sterile neutrinos and the seesaw mechanism. In tritium β decay, interference between left- and right-handed currents thus leads to slightly modified kinematics, which enhances or suppresses certain regions near the endpoint of the beta spectrum. In this work, the sensitivity of KATRIN to right-handed currents is estimated for the scenario of a sterile neutrino with a mass of some eV. This has been performed with a Bayesian analysis using Markov Chain Monte Carlo (MCMC). The sensitivity and parameter correlations are further discussed under the hypothetical premise of a constrained tritium Q-value and with respect to the lack of knowledge about the sterile neutrino mass. The results are compared with current experimental limits on right-handed weak bosons.