Search for a Doubly Charged Scalar at the LHC and FCC-hh

TL;DR

This paper assesses the potential of the LHC and FCC-hh colliders to detect doubly charged scalars, which are key to understanding neutrino mass origins, through their leptonic decay signatures.

Contribution

It provides a detailed sensitivity analysis of current and future colliders for discovering doubly charged scalars, highlighting FCC-hh's capability to probe up to 7 TeV masses.

Findings

FCC-hh can probe doubly charged scalars up to 7 TeV

LHC full run II sensitivity includes photon-photon fusion effects

FCC-hh could potentially reveal the neutrino mass mechanism

Abstract

Doubly charged scalars frequently emerge in many well-motivated extensions of the Standard Model, particularly in frameworks that aim to explain the origin of neutrino masses. Their distinct electric charge and clean leptonic signatures make them especially compelling from the standpoint of experimental searches. In this work, we explore the sensitivity of the LHC full run II, including photon-photon fusion, and Future Circular Collider in its hadron-hadron configuration (FCC-hh) to such states, assuming they decay promptly and exclusively into charged leptons either conserving or violating lepton flavor. We find that the FCC-hh, operating at 100 TeV, is uniquely positioned to probe doubly charged scalars with masses up to 7 TeV and possibly establish the mechanism behind neutrino masses.