Measurement of the inclusive jet cross section in pp collisions at $\sqrt{s}=2.76$TeV and comparison to the inclusive jet cross section at $\sqrt{s}=7$TeV using the ATLAS detector

The inclusive jet cross section has been measured in proton-proton collisions at a centre-of-mass energy of $\sqrt{s} = 2.76$ TeV using the ATLAS detector at the Large Hadron Collider at CERN. The measurement is performed using a dataset with a total integrated luminosity of $0.20\,pb^{-1}$ collected in 2011. The anti-$k_{t}$ algorithm is used to identify jets with two jet distance parameters, $R = 0.4$ and $R = 0.6$. The inclusive single-jet double-differential cross section is presented as a function of the jet transverse momentum $p_{T}$ and rapidity $y$, in the range of $20\leq p_{T} < 430$ GeV and $|y| < 4.4$. The ratio of the measured cross section is taken to the inclusive jet cross section measurement at $\sqrt{s} = 7$ TeV published by the ATLAS collaboration. Due to the cancellation of correlated uncertainties in the two measurements, the systematic uncertainties are significantly reduced in the jet cross section ratio. Results are compared to predictions from next-to-leading order perturbative QCD, corrected for non-perturbative effects. The measured jet cross section and the published ATLAS jet cross section at $\sqrt{s}=7$ TeV are analysed together within a framework of next-to-leading order perturbative QCD.