Search for resonant diboson production in the $\ell\ell q\bar{q}$ final state in $pp$ collisions at $\sqrt{s}=8$ TeV with the ATLAS detector

A search for resonances in diboson production in the $\ell\ell q\bar{q}$ final state using 20.3 fb$^{-1}$ of $pp$ collision data collected at $\sqrt{s}=8$ TeV with the ATLAS detector is reported. No significant excess over the Standard Model expectation is observed. Consequently 95% confidence level upper limits are set on the cross section times branching ratio for the production of Kaluza-Klein gravitons in the Randall-Sundrum model and extended gauge model $W'$ bosons, leading to the exclusion of mass values below 740 and 1590 GeV for the graviton and $W'$ boson, respectively.