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

## TL;DR

This paper explores how future electron-positron colliders can distinguish different new physics effects in Majorana neutrino production by analyzing final anti-tau polarization and initial beam polarization, focusing on effective operators.

## Contribution

It introduces a method to differentiate vectorial and scalar operator contributions in Majorana neutrino production using polarization signatures at future colliders.

## Key findings

- Polarization analyses can distinguish operator types.
- Effective operators influence polarization signatures.
- Method enhances understanding of new physics contributions.

## 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 $e^{+}e^{-}\rightarrow l^{+} l^{+}+ 4 jets$, 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.