Search for Charged Higgs Bosons in the $\tau$+jets Final State in $t\overline{t}$ Decays with 1.03 fb$^{-1}$ of $pp$ Collision Data Recorded at $\sqrt{s} = 7$ TeV with the ATLAS Experiment

This note presents the results of a search for charged Higgs bosons, $H^{\pm}$, in 1.03 fb$^{-1}$ of proton-proton collision data recorded at $\sqrt{s}=7$ TeV with the ATLAS experiment at the LHC using the $\tau$+jets channel in $t\overline{t}$ decays with a hadronically decaying $\tau$ lepton in the final state. The data agree with the SM expectation leading to a limit on the product of branching ratios BR($t \to bH^{\pm}) \times$ BR($H^\pm \to \tau\nu$) of $0.03-0.10$ for $H^\pm$ masses in the range $90 \GeV<m_{H^\pm}<160 \GeV$. In the context of the MSSM values of $\tan \beta$ larger than $22-30$ are excluded in the mass range $90 \GeV< m_{H^\pm}< 140 \GeV$.