$\mathbf{ H^\pm \rightarrow \chi^\pm \chi^0 \to 3\ell + E_{\mathrm{T}}^{\mathrm{miss}}}$ Searches

\def\met{\not\!\!{E_{T}}} In some supersymmetric (SUSY) models, a charged Higgs boson ($\rm H^\pm$) can decay into a chargino-neutralino ($\rm\chi^\pm_i \chi^0_j $) pair producing a final state containing three leptons (electron/muon) and missing transverse energy ($3\ell+\met$). Such a decay could provide extra sensitivity to the $\rm H^\pm$ in the region of SUSY parameter space near tan$\beta$ = 7, where the $\rm H^\pm$ Standard Model decays have reduced significance. We present a signature search on early ATLAS data, setting an exclusion limit on an excess of $3\ell+\met$ events over the Standard Model background. Such an excess could be evidence of generic SUSY, the $\rm H^\pm \to \chi^\pm_i \chi^0_j$ decay, or both.