# Probing Neutrino Dirac Mass in Left-Right Symmetric Models at the LHC and Next Generation Colliders

## TL;DR

This paper evaluates the potential of current and future colliders to measure the Dirac Yukawa coupling of heavy neutrinos in left-right symmetric models, highlighting the need for a 100 TeV collider for direct probing.

## Contribution

It provides a detailed analysis of collider sensitivities to the Dirac Yukawa coupling in LRSMs, emphasizing the importance of a 100 TeV collider for direct measurements.

## Key findings

- LHC can discover $W_R$ but not probe Dirac Yukawa couplings
- A 100 TeV collider is required to directly measure the Dirac Yukawa coupling
- Detection of trilepton signals at LHC suggests non-minimal LRSM scenarios

## Abstract

We assess the sensitivity of the LHC, its high energy upgrade, and a prospective 100 TeV hadronic collider to the Dirac Yukawa coupling of the heavy neutrinos in left-right symmetric models (LRSMs). We focus specifically on the trilepton final state in regions of parameter space yielding prompt decays of the right-handed gauge bosons ($W_R$) and neutrinos ($N_R$). In the minimal LRSM, the Dirac Yukawa couplings are completely fixed in terms of the mass matrices for the heavy and light neutrinos. In this case, the trilepton signal provides a direct probe of the Dirac mass term for a fixed $W_R$ and $N_R$ mass. We find that while it is possible to discover the $W_R$ at the LHC, probing the Dirac Yukawa couplings will require a 100 TeV $pp$ collider. We also show that the observation of the trilepton signal at the LHC would indicate the presence of a non-minimal LRSM scenario.