Search for squarks and gluinos with the ATLAS detector in final states with jets and missing transverse momentum and 20.3 fb$^{-1}$ of $\sqrt{s}=8$ TeV proton-proton collision data

A search for squarks and gluinos in final states containing high-$p_T$ jets, missing transverse momentum and no electrons or muons is presented. The data were recorded in 2012 by the ATLAS experiment in $\sqrt{s}=8$ TeV proton-proton collisions at the Large Hadron Collider, with a total integrated luminosity of 20.3 fb$^{-1}$. No significant excess above the Standard Model expectation is observed. In a simplified model with only gluinos and the lightest neutralino, gluino masses below 1350 GeV are excluded at the 95% confidence level when the lightest neutralino is massless. For a simplified model involving the strong production of squarks of the first two generations, with decays to a massless lightest neutralino, squark masses below 780 GeV are excluded. In MSUGRA/CMSSM models with $\tan\beta=30$, $A_0=-2m_0$ and $\mu> 0$, squarks and gluinos of equal mass are excluded for masses below 1700 GeV. These limits extend the region of supersymmetric parameter space excluded by previous searches with the ATLAS detector.