Measurement of the k_t splitting scales in Z ℓℓ events in pp collisions at √s̅ = 8 TeV with the ATLAS detector

A measurement of the splitting scales occuring in the k_t jet-clustering algorithm is presented for final states containing a Z boson. The measurement is done using 20.2 fb⁻¹ of proton-proton collision data collected at a centre-of-mass energy of √s = 8 TeV by the ATLAS experiment at the LHC in 2012. The measurement is based on chargedparticle track information, which is measured with excellent precision in the p _T region relevant for the transition between the perturbative and the non-perturbative regimes. The data distributions are corrected for detector effects, and are found to deviate from state-of-the-art predictions in various regions of the observables.