A Truly Minimal Left-Right Symmetric Extension of the Standard Model

TL;DR

This paper proposes a minimal Left-Right symmetric extension of the Standard Model, requiring only two Higgs bosons and predicting a light Higgs, while remaining indistinguishable from the Standard Model at current energies.

Contribution

It introduces a minimal model based on custodial symmetry with only two Higgs bosons, simplifying the Higgs sector of Left-Right symmetric theories.

Findings

Predicts a small-mass Higgs accessible via perturbation theory

Reproduces fermion masses with ad hoc fermion-Higgs interactions

Remains indistinguishable from the Standard Model at current energies

Abstract

By invoking the existence of a general custodial O(2) symmetry, a minimal Left-Right symmetric model based on the gauge group G=SU(2)L SU(2)R U(1)BL is shown to require the existence of only two physical Higgs bosons. The lighter Higgs is predicted to have a small mass which could be evaluated by standard perturbation theory. The fermionic mass matrices are recovered by insertion of ad hoc fermion-Higgs interactions. The model is shown to be undistinguishable from the standard model at the currently reachable energies.