Search for doubly-charged Higgs bosons in like-sign dilepton final states at sqrt(s) = 7 TeV with the ATLAS detector

TL;DR

This paper reports a search for doubly-charged Higgs bosons decaying into same-sign dileptons at 7 TeV, setting mass limits and excluding certain mass ranges based on the ATLAS detector data.

Contribution

It provides the first limits on doubly-charged Higgs boson masses in like-sign dilepton channels at the LHC with 7 TeV data.

Findings

No significant excess observed over background.

Masses below 409 GeV, 375 GeV, and 398 GeV excluded for ee, emu, mumu channels.

Limits depend on the assumed branching ratios and production mechanisms.

Abstract

A search for doubly-charged Higgs bosons decaying to pairs of electrons and/or muons is presented. The search is performed using a data sample corresponding to an integrated luminosity of 4.7 fb-1 of pp collisions at sqrt(s) = 7 TeV collected by the ATLAS detector at the LHC. Pairs of prompt, isolated, high-pT leptons with the same electric charge (ee, emu, mumu) are selected, and their invariant mass distribution is searched for a narrow resonance. No significant excess over Standard Model background expectations is observed, and limits are placed on the cross section times branching ratio for pair production of doubly-charged Higgs bosons. The masses of doubly-charged Higgs bosons are constrained depending on the branching ratio into these leptonic final states. Assuming pair production, coupling to left-handed fermions, and a branching ratio of 100% for each final state, masses below 409 GeV, 375 GeV, and 398 GeV are excluded for ee, emu, mumu, respectively.