Search for a dijet resonance produced in association with a leptonically decaying $W$ or $Z$ boson with the ATLAS detector at $\sqrt{s} = 8$ TeV

A search for a dijet resonance with an invariant mass in the range between 130 and 300~GeV is performed in the processes $pp \to Wjj+X$ with $W \to \ell^{\pm}\nu$ and $pp \to Zjj+X$ with $Z \to \ell^+\ell^-$ ($\ell = e, \mu$). The data used correspond to 20.3 fb$^{-1}$ of $pp$ collision data recorded at $\sqrt{s}=$8~TeV with the ATLAS detector at the CERN Large Hadron Collider. The results are interpreted in terms of constraints on the Low Scale Technicolor model. No significant deviation from the Standard Model background prediction is observed. Upper limits on the production cross section times branching fraction are set for a hypothetical technipion produced in association with a $W$ or $Z$ boson from the decay of a technirho particle.