Final taus and initial state polarization signatures from effective interactions of Majorana neutrinos at future $e^{+}{e}^{-}$ colliders

Abstract

We study the possibility of future $e^{+}{e}^{-}$ colliders to disentangle different new physics contributions to the production of heavy sterile Majorana neutrinos in the lepton number violating channel $e^{+}{e}^{-}\to l^{+}{l}^{+}+4jets$, with $l=e,\mu ,\tau$. This is done investigating the final anti-tau polarization trails and initial beam polarization dependence of the signal on effective operators with distinct Dirac-Lorentz structure contributing to the Majorana neutrino production and decay, which parameterize new physics from a higher energy scale. We find both analyses could well disentangle possible vectorial and scalar operators contributions.

21 pages, 11 figures. arXiv admin note: text overlap with arXiv:1802.07620