Polarized window for left-right symmetry and a right-handed neutrino at the Large Hadron-Electron Collider

TL;DR

This paper proposes using the Large Hadron-Electron Collider to detect heavy right-handed neutrinos, providing a direct test of left-right symmetry breaking through a clean, lepton number violating signal enhanced by polarized electron beams.

Contribution

It demonstrates that polarized electron beams at LHeC can effectively produce and identify right-handed neutrinos, offering a novel method to probe left-right symmetric theories.

Findings

Right-handed neutrino production can be detected at LHeC.

Polarized electron beams improve signal clarity and production rates.

Lepton number violation signal is background-free.

Abstract

The breaking of parity, a fundamental symmetry between left and right is best understood in the framework of left-right symmetric extension of the standard model. We show that the production of a heavy right-handed neutrino at the proposed Large Hadron-Electron Collider (LHeC) could give us the most simple and direct hint of the scale of this breaking in left-right symmetric theories. This production mode gives a lepton number violating signal with $\Delta L=2$ which is very clean and has practically no standard model background. We highlight that the right-handed nature of $W_R$ exchange which defines the left-right symmetric theories can be confirmed by using a polarized electron beam and also enhance the production rates with relatively lower beam energy.