Study of the channel $H\rightarrow Z^{*}Z \rightarrow \ell^+\ell^- q\bar{q}$ in the mass range 120-180 GeV with the ATLAS Detector at $\sqrt{s}$=7 TeV

A study of the decay channel $H \rightarrow Z^{*}Z\rightarrow\ell^+\ell^- q \bar{q}$ ($\ell=e,\mu$) is presented, with the mass of the Higgs boson between 120 $GeV$ and 180 $GeV$, using the $pp$ collision data collected by the ATLAS experiment at $\sqrt{s}=7~TeV$. Data-driven methods for the background estimation, as well as new techniques to improve the mass resolution of the hadronic $Z$ boson decays, are used. Events with 0 or 1 b-jets and events with 2-bjets are treated as separate channels. No significant excess of events above the estimated background is observed; upper limits at 95\% C.L. on the Higgs production cross section are derived.