Multi-Lepton Signals of the Higgs Boson

TL;DR

This paper evaluates the potential of multi-lepton channels at the LHC for Higgs boson discovery, showing that combined signals across various final states can achieve competitive sensitivity with existing methods.

Contribution

It demonstrates that combining multiple non-resonant multi-lepton channels enhances Higgs detection sensitivity beyond individual channels, providing a new approach to Higgs searches.

Findings

Multi-lepton signals can surpass four-lepton mode in total sensitivity.

Combined multi-channel analysis can exclude Higgs at 95% CL with existing data.

Patterns in production and decay modes can be discerned through channel correlations.

Abstract

The possibility of searching for the Higgs boson in channels with multiple non-resonant leptons is evaluated in light of recent advances in multi-lepton search techniques at the LHC. The total multi-lepton Higgs signal exceeds the four lepton gold-plated resonant mode, but is spread over many channels with same-sign di-lepton, tri-lepton, and four lepton final states. While any individual channel alone is not significant, the exclusive combination across multiple channels is shown to provide a sensitivity competitive with other discovery level searches for the Higgs boson. We estimate that with 5 inverse femtobarn of data, existing non-optimized multi-lepton searches at the LHC could exclude the Higgs boson to 95% CL at a few times the predicted Standard Model cross section in the mass range 120-150 GeV. Refinements focused specifically on the Higgs boson signal are suggested that would further increase sensitivity. We illustrate the possibility of discerning patterns in production and decay modes using correlations across multiple channels by comparing sensitivities to Standard Model, Fermi-phobic, and b-phobic Higgs bosons.