Search for charged Higgs bosons decaying via H+ -> tau nu in top quark pair events using pp collision data at sqrt(s) = 7 TeV with the ATLAS detector

TL;DR

This paper reports a search for charged Higgs bosons decaying to tau neutrinos in top quark pair events at 7 TeV, setting upper limits on their production and excluding certain MSSM parameter regions.

Contribution

First search using 7 TeV pp collision data to set limits on charged Higgs bosons decaying to tau neutrinos in top quark events.

Findings

No significant excess over Standard Model background.

Upper limits on top quark decays to charged Higgs bosons between 1% and 5%.

Excluded MSSM parameter regions for certain tan(beta) and mass ranges.

Abstract

The results of a search for charged Higgs bosons are presented. The analysis is based on 4.6/fb of proton-proton collision data at sqrt(s) = 7 TeV collected by the ATLAS experiment at the Large Hadron Collider, using top quark pair events with a tau lepton in the final state. The data are consistent with the expected background from Standard Model processes. Assuming that the branching ratio of the charged Higgs boson to a tau lepton and a neutrino is 100%, this leads to upper limits on the branching ratio of top quark decays to a b quark and a charged Higgs boson between 5% and 1% for charged Higgs boson masses ranging from 90 GeV to 160 GeV, respectively. In the context of the mh-max scenario of the MSSM, tan(beta) above 12-26, as well as between 1 and 2-6, can be excluded for charged Higgs boson masses between 90 GeV and 150 GeV.