Search for doubly and singly charged Higgs bosons decaying into vector bosons in multi-lepton final states with the ATLAS detector using proton-proton collisions at $\sqrt{s}$ = 13 TeV

TL;DR

This paper reports a search for charged Higgs bosons decaying into vector bosons using ATLAS data at 13 TeV, setting mass exclusion limits up to 350 GeV without observing significant deviations from the Standard Model.

Contribution

It provides the first comprehensive search for doubly and singly charged Higgs bosons in multi-lepton final states within the type-II seesaw model at 13 TeV.

Findings

No significant excess observed over Standard Model predictions.

Excludes doubly charged Higgs bosons up to 350 GeV.

Excludes singly charged Higgs bosons up to 230 GeV.

Abstract

A search for charged Higgs bosons decaying into $W^\pm W^\pm$ or $W^\pm Z$ bosons is performed, involving experimental signatures with two leptons of the same charge, or three or four leptons with a variety of charge combinations, missing transverse momentum and jets. A data sample of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded with the ATLAS detector at the Large Hadron Collider between 2015 and 2018 is used. The data correspond to a total integrated luminosity of 139 fb$^{-1}$. The search is guided by a type-II seesaw model that extends the scalar sector of the Standard Model with a scalar triplet, leading to a phenomenology that includes doubly and singly charged Higgs bosons. Two scenarios are explored, corresponding to the pair production of doubly charged $H^{\pm\pm}$ bosons, or the associated production of a doubly charged $H^{\pm\pm}$ boson and a singly charged $H^\pm$ boson. No significant deviations from the Standard Model predictions are observed. $H^{\pm\pm}$ bosons are excluded at 95% confidence level up to 350 GeV and 230 GeV for the pair and associated production modes, respectively.