Search for charged Higgs bosons decaying into a top quark and a bottom quark at $\sqrt{s}$=13 TeV with the ATLAS detector

TL;DR

This paper reports a search for charged Higgs bosons decaying into top and bottom quarks using 13 TeV proton-proton collision data from the ATLAS detector, setting exclusion limits across a wide mass range.

Contribution

First search to analyze the full Run 2 dataset for charged Higgs bosons decaying into top and bottom quarks at 13 TeV with advanced multivariate techniques.

Findings

No significant excess observed above background.

Exclusion limits set on production cross-section times branching ratio.

Limits range from 3.6 pb at 200 GeV to 0.036 pb at 2000 GeV.

Abstract

A search for charged Higgs bosons decaying into a top quark and a bottom quark is presented. The data analysed correspond to 139 fb$^{-1}$ of proton-proton collisions at $\sqrt{s}$=13TeV, recorded with the ATLAS detector at the LHC. The production of a heavy charged Higgs boson in association with a top quark and a bottom quark, $pp\rightarrow tbH^{+}\rightarrow tbtb$, is explored in the $H^+$ mass range from 200 to 2000 GeV using final states with jets and one electron or muon. Events are categorised according to the multiplicity of jets and $b$-tagged jets, and multivariate analysis techniques are used to discriminate between signal and background events. No significant excess above the background-only hypothesis is observed and exclusion limits are derived for the production cross-section times branching ratio of a charged Higgs boson as a function of its mass; they range from 3.6 pb at 200 GeV to 0.036 pb at 2000 GeV at 95% confidence level. The results are interpreted in the hMSSM and $M_h^{125}$ scenarios.