Search for Doubly-Charged Higgs Bosons at LEP

TL;DR

This paper reports a search for doubly-charged Higgs bosons at LEP using e^+e^- collision data, setting lower mass limits and finding no evidence for their existence within the analyzed energy range.

Contribution

It provides new experimental lower bounds on the mass of doubly-charged Higgs bosons and constrains their possible couplings based on LEP data.

Findings

Lower mass limits between 95.5 GeV and 100.2 GeV depending on decay mode.

No significant excess observed in four-lepton final states.

Doubly-charged Higgs bosons with masses up to about 1 TeV are excluded.

Abstract

Doubly-charged Higgs bosons are searched for in e^+e^- collision data collected with the L3 detector at LEP at centre-of-mass energies up to 209 GeV. Final states with four leptons are analysed to tag the pair-production of doubly charged Higgs bosons. No significant excess is found and lower limits at 95% confidence level on the doubly-charged Higgs boson mass are derived. They vary from 95.5 GeV to 100.2 GeV, depending on the decay mode. Doubly-charged Higgs bosons which couple to electrons would modify the cross section and forward-backward asymmetry of the e^+e^- -> e^+e^- process. The measurements of these quantities do not deviate from the Standard Model expectations and doubly-charged Higgs bosons with masses up to the order of a TeV are excluded.