Measurement of the ratio of inclusive jet cross sections using the anti- k T algorithm with radius parameters R=0.5 and 0.7 in pp collisions at s =7TeV

Measurements of the inclusive jet cross section with the anti-k(T) clustering algorithm are presented for two radius parameters, R = 0.5 and 0.7. They are based on data from LHC proton-proton collisions at root s = 7 TeV corresponding to an integrated luminosity of 5.0 fb(-1) collected with the CMS detector in 2011. The ratio of these two measurements is obtained as a function of the rapidity and transverse momentum of the jets. Significant discrepancies are found comparing the data to leading-order simulations and to fixed-order calculations at next-to-leading order, corrected for nonperturbative effects, whereas simulations with next-to-leading-order matrix elements matched to parton showers describe the data best.