Search for charged Higgs bosons in ATLAS

Charged Higgs bosons are predicted in several extensions of the Standard Model, where the Higgs sector contains more than one doublet of complex scalars, for instance in the Minimal Supersymmetric Standard Model (MSSM). For $m_{H^+} < m_{\mathrm{top}}$, the dominant production mode for charged Higgs bosons at the LHC is via the decay $t\rightarrow bH^+$ of one of the top quarks in $t\bar{t}$ events. We present results on the search for such light charged Higgs bosons in the ATLAS experiment, with emphasis on the decay $H^+ \rightarrow \tau \nu$.