Abstract
Abstract:
A search for doubly charged Higgs bosons with pairs of prompt, isolated, highly energetic
leptons with the same electric charge is presented. The search uses a proton–proton collision data
sample at a centre-of-mass energy of 13 TeV corresponding to 36.1 fb−1 of integrated luminosity
recorded in 2015 and 2016 by the ATLAS detector at the LHC. This analysis focuses on the decays H±±
→ e±e±, H±± → e±µ± and H±± → µ±µ±, fitting the dilepton mass spectra in several exclusive signal
regions. No significant evidence of a signal is observed and corresponding limits on the production
cross-section and consequently a lower limit on m(H±±) are derived at 95% confidence level. With
f±f± = e±e±/µ±µ±/e±µ±, the observed lower limit on the mass of a doubly charged Higgs boson only
coupling to left-handed leptons varies from 770 GeV to 870 GeV (850 GeV expected) for B(H±± → f±f±)
= 100% and both the expected and observed mass limits are above 450 GeV for B(H±± → f±f±) = 10%
and
any combination of partial branching ratios.