Journal Article

Multi-lepton production and a search for doubly-charged Higgs at HERA

Sztuk-Dambietz, J

2008

Overview

Events with two or more leptons (electrons or muons) with high transverse momentum are measured in electron-proton collisions at HERA using the data samples collected in the period 1994-2007. Yields of di-lepton and tri-lepton events are investigated and a general good agreement is found with the Standard Model (SM) prediction. Multi-lepton events at high transverse momenta, where the SM prediction is low, are of special interest as these signature might reveal new physics beyond the Standard Model. An example is the single production of a doubly-charged Higgs boson (H±±) decaying into a high mass pair of same charge leptons. This possibility has been investigated and H±± decays involving electrons, muons and taus are considered. No evidence for doubly-charged Higgs production is observed and mass-dependent upper limits are derived on the Yukawa couplings hij of the Higgs boson to leptons of flavour i and j.

• Publisher: IOP Publishing
• Subject: Couplings / Electrons / Flavor (particle physics) / Higgs bosons / Leptons / Muons / Physics / Quarks / Standard model (particle physics) / Transverse momentum